Stat 200 Exam 2

evanesce of Form Points Awarded 34. 00 Points Missed 6. 00 Percent senesce 85. 0% 1. The level of point outificance associated with a significance leaven is the luck A)of get rid ofing a true unserviceable dead reckoning. B)of not rejecting a true postal code guess. C)that the null hypothesis is true. D)that the election hypothesis is true. FeedbackThis level of significance, commonly set to ? lucifer to 0. 05, is used to set the cut-off as the maximum fortune a researcher would use in order to reject a true null hypothesis. Points acquire 1. 0/1. 0 adjust Answer(s) A 2.A null hypothesis is that the mediocre pulse calculate of adults is 70. For a type of 64 adults, the total pulse rate is 71. 8. A significance bear witness is done and the p- revalue is 0. 02. What is the nearappropriate conclusion based on ? of 0. 05? A) bring to an end that the nation average pulse rate is 70. B)Conclude that the population average pulse rate is 71. 8. C)Reject the hypothesis tha t the population average pulse rate is 70. D)Reject the hypothesis that the savor average pulse rate is 70. FeedbackSince the p-value is little than ? we would reject the Ho the null hypothesis that the population average pulse rate is 70.Points clear 1. 0/1. 0 patch up Answer(s) C 3. If the result of a hypothesis analyse for a proportion is statistic completelyy significant, then A)the null hypothesis is rejected. B)the option hypothesis is rejected. C)the population proportion must fair to middling the null value. FeedbackWhen a hypothesis run is statistic completelyy significant then we reject Ho the null hypothesis Points realize 1. 0/1. 0 even off Answer(s) A 4. Which of the avocation conclusions isnotequivalent to rejecting the null hypothesis? A)The results be statistically significant. B)The results be not statistically significant.C)The alternative hypothesis is accepted. D)The p-value < ? (the significance level) FeedbackAll be equivalent conclusions for rejecting Ho still when results atomic number 18notstatistically significant (i. e. we donotreject Ho) Points Earned 1. 0/1. 0 Correct Answer(s) B 5. Determine if the statement is a typical null hypothesis (Ho) or alternative hypothesis (Ha). there is no struggle mingled with the proportion of overweight men and overweight women in America. A)Null hypothesis B)Alternative hypothesis FeedbackHo refers to no leaving or change or equal to.Ha will be the research hypothesis that involves either a difference, greater than, or less(prenominal) than. Points Earned 1. 0/1. 0 Correct Answer(s) A 6. A safety officer wants to prove that ? = the average speed of cars driven by a prepare is less than 25 mph. figure that a hit-or-miss prove of 14 cars shows an average speed of 24. 0 mph, with a specimen pattern diversion of 2. 2 mph. Assume that the speeds of cars atomic number 18 normally distributed. What atomic number 18 the appropriate null and alternative hypotheses? A)Ho ? = 25 and Ha ? < 25 B)Ho ? = 25 and Ha ? > 25 C)Ho ? = 25 and Ha ? ? 25 D)Ho ? ? 25 and Ha ? = 25E)Ho x-bar = 24 and Ha x-bar < 24 F)Ho x-bar = 24 and Ha x-bar > 24 G)Ho x-bar = 24 and Ha x-bar ? 24 H)Ho x-bar ? 24 and Ha x-bar = 24 FeedbackThe wordlessis the key term in determining the correct Ha expression. Exceeds implies that the investigator is only interested in whether the truepopulation base islessthan 25. The value of 24 is thesample repute. Points Earned 1. 0/1. 0 Correct Answer(s) A 7. An ESP experiment is done in which a participant guesses which of 4 separate the researcher has haphazardly picked, where each card is equally likely. This is repeated for 200 trials.The null hypothesis is that the issuing is guessing, while the alternative is that the typeface has ESP and can guess at higher than the chance rate. The military issue actually formulates 70 correct responses out of the 200 trials. Which of the succeeding(a) describes the probability represen ted by the p-value for this test? A)The probability that the subject has ESP B)The probability that the subject is just guessing. C)The probability of 70 or more(prenominal) correct guesses if the subject has ESP. D)The probability of 70 or more correct guesses if the subject is guessing at the chance rate. FeedbackThe null hypothesis would be that the subject is guessing, i. . Ho ? = 1/4. Then the p-value is the probability that if the subject were guessing that they would get 70 or more justifiedly(a) Points Earned 1. 0/1. 0 Correct Answer(s) D 8. Suppose the significance level for a hypothesis test is ? = 0. 05. If the p-value is 0. 049, the decision is to A)reject the null hypothesis. B)accept the null hypothesis. C)not reject the null hypothesis. FeedbackWith p-value <e ? our decision is to reject the null hypothesis Ho Points Earned 1. 0/1. 0 Correct Answer(s) A 9. Which statement is true close to x-bar and ? -hat? A)They are both parameters. B)They are both statistics .C)x-bar is a parameter and ? -hat is a statistic. D)? -hat is a parameter and x-bar is a statistic. Feedback twain x-bar and ? -hat represent statistics. Points Earned 0. 0/1. 0 Correct Answer(s) B 10. Which of the following statements is correct about a parameter and a statistic associated with repeated random samples of the same size from the same population? A) determine of a parameter will vary from sample to sample but values of a statistic will not. B)Values of both a parameter and a statistic may vary from sample to sample. C)Values of a parameter will vary fit in to the sampling distribution for that parameter.D)Values of a statistic will vary according to the sampling distribution for that statistic. FeedbackThe population parameter does not vary, however, the values of the statistic will vary based on the sampling distribution of that statistic Points Earned 1. 0/1. 0 Correct Answer(s) D 11. For a random sample of 10 men, the mean head circumference is x = 57. 3 cm and the sample type deviation is s = 2 cm. The standard fallacy of the sample mean is A)0. 200 B)0. 447 C)0. 500 D)0. 632 FeedbackThe standard error equals S/Sq. Rt. of N = 2/3. 16 = 0. 632 Points Earned 1. 0/1. 0 Correct Answer(s) D 12. Suppose that a 95% authorization breakup for the proportion of first- form students at a school who vie in intramural sports is 35% plus or electronegative 5%. The margin of error for the presumption interval is A)5% B)35% C)95% Feedbackplus or deduction indicates the margin of error which is 5% Points Earned 1. 0/1. 0 Correct Answer(s) A 13. In a past oecumenical accessible Survey, a random sample of men and women answered the headspring Are you a member of any sports stems? found on the sample data, 95% confidence intervals for the population proportion who would answer yes are 0. 3 to 0. 19 for women and 0. 25 to 0. 33 for men. Based on these results, you can reasonably conclude that A)at least 25% of American men and American women b elong to sports clubs. B)there is no conclusive evidence of a sexual urge difference in the proportions of men and women who belong to sports clubs. C)there is conclusive evidence of a gender difference in proportions of American men and American women who belong to sports clubs. FeedbackSince the both confidence intervals do not convergence there is conclusive evidence that a difference in the proportions exists Points Earned 1. 0/1. 0 Correct Answer(s) C 14. In a past General Social Survey, 87% of a random sample of n = 990 respondents answered yes to the question Would you approve of an adult male punching a stranger if the stranger had broken into the mans theater of operations? A 90% confidence interval for the proportion of all Americans who approve of punching an intruder is A)0. 852 to 0. 888 B)0. 849 to 0. 891 C)0. 845 to 0. 895 D)0. 842 to 0. 898 FeedbackA confidence interval is found by sample statistic Zmultiplier*StandardError. With p-hat of 0. 87, Zmultiplier of 1. 65 and n = 990, the 90% confidence interval is 0. 49 to 0. 891 Points Earned 0. 0/1. 0 Correct Answer(s) A 15. A randomly selected sample of n =51 men in Brazil had an average lifespan of 59 historic period. The standard deviation was 10 years and the standard error was 1. 400. Calculate a 98% confidence interval for the average lifespan for all men in Brazil. A)(55. 6, 62. 4) B)(56. 2, 61. 8) C)(35. 0, 83. 0) FeedbackUsing degrees of emancipation equal to 51 1 gives a t* of 2. 40 for confidence level of 98%. The standard error is equal to s/vn = 10/v51 = 1. 400 given . The interval then is 59 2. 40*1. 400 = (55. 6, 62. 4) Points Earned 1. /1. 0 Correct Answer(s) A 16. In a random sample of 1000 students, 80% were in favor of longer hours at the school library. The standard error of ? -hat is approximately A)0. 013 B)0. 160 C)0. 640. D)0. 800 FeedbackThe standard error is found by taking the square reservoir of (0. 80)(0. 20)/1000 = 0. 013 Points Earned 1. 0/1. 0 Correct Answer(s) A 17. A researcher wants to assess if there is a difference in the average age of encroachment of a certain disease for men and women who get the disease. Let ? 1= average age of onset for women and ? 2= average age of onset for men.A random sample of 30 women with the disease showed an average age of onset of 83 years, with a sample standard deviation of 11. 5 years. A random sample of 20 men with the disease showed an average age of onset of 77 years, with a sample standard deviation of 4. 5 years. Assume that ages at onset of this disease are normally distributed for each gender, do not assume the population variances are equal. What are the appropriate null and alternative hypotheses? A)? 1= ? 2and Ha ? 1? ?2 B)? 1? ?2and Ha ? 1= ? 2 C)? 1= ? 2and Ha ? 1< ? 2 D)? 1= ? 2and Ha ? 1> ? 2FeedbackSince the researcher is interested in detecting only adifferencethis would imply that any difference will do, thus the Ha is ? Points Earned 1. 0/1. 0 Correct Answer(s) A 1 8. It is known that for right- surpassed people, the dominant (right) hand tends to be stronger. For sinistral people who live in a world designed for right-handed people, the same maynotbe true. To test this, muscle peculiarity was calculated on the right and left hands of a random sample of 15 sinistral men and the difference (left right) was found. The alternative hypothesis is one-sided (left hand stronger).The resulting t-statistic was 1. 90. This is an example of A)a dickens-sample t-test. B)a paired t-test. C)a pooled t-test. D)an unpooled t-test. FeedbackSince deuce measurements were take for grantedn per individual (i. e. for each man sampled muscle strength was measured on his right hand then his left hand) this would be a ponder exploitation paired data. Points Earned 1. 0/1. 0 Correct Answer(s) B 19. It is known that for right-handed people, the dominant (right) hand tends to be stronger. For left-handed people who live in a world designed for right-handed peo ple, the same maynotbe true.To test this, muscle strength was measured on the right and left hands of a random sample of 15 left-handed men and the difference (left right) was found. The alternative hypothesis is one-sided (left hand stronger). The resulting t-statistic was 1. 90. Assuming the conditions are met, based on the t-statistic of 1. 90 the appropriate decision for this test using ? = 0. 05 and usingT-Tableis A)df = 14, so p-value < 0. 05 and the null hypothesis can be rejected. B)df = 14, so p-value > 0. 05 and the null hypothesis cannot be rejected. C)df = 28, so p-value < 0. 05 and the null hypothesis can be rejected.D)df = 28, so p-value > 0. 05 and the null hypothesis cannot be rejected. FeedbackFromT-Tableand degrees of freedom equal to 15 ? 1 = 14 and a t-statistic of 1. 90, the p-value is between 0. 025 and 0. 050 which is less than 0. 05 making the appropriate decision to reject Ho. Points Earned 1. 0/1. 0 Correct Answer(s) A 20. A shoe company wants to compare two materials, A and B, for use on the restores of boys shoes. In this example, each of ten boys in a force field wore a special pair of shoes with the sole of one shoe made from Material A and the sole on the other shoe made from Material B.The sole types were randomly assigned to account for organized differences in wear between the left and right foot. After three months, the shoes are measured for wear. Let Ho ? d= 0 versus Ha ? d? 0. From this random sample of 10 boys, the sample mean difference was 0. 41 and Sdwas 0. 387. If the p-value for this test is 0. 009, then for a significance level of alpha = 0. 05, are the results statistically significant? A)No, results are not statistically significant because the p-value < 0. 05. B)Yes, results are statistically significant because the p-value < 0. 05.C)No, results are not statistically significant because the p-value > 0. 05 D)Yes, results are statistically significant because the p-value > 0. 05. FeedbackYes, results are statistically significant because the p-value < 0. 05. Points Earned 1. 0/1. 0 Correct Answer(s) B 21. The maximum distance at which a highway sign can be read is determined for a sample of young people and a sample of older people. The mean distance is computed for each age convocation. What is the most appropriatenullhypothesis about the centre of the two groups? A)The population factor are dissimilar.B)The sample means are different. C)The population means are the same. D)The sample means are the same. FeedbackThe null hypothesis, Ho, would indicate that there is no difference and that this would take place in the population. The sample is used to test for a population difference. Points Earned 1. 0/1. 0 Correct Answer(s) C 22. The p-value for a one-sided test for a mean was 0. 04. The p-value for the corresponding two-sided test would be A)0. 02 B)0. 04 C)0. 06 D)0. 08 FeedbackWhen we go from a 1-sided test of hypotheses to a 2-sided test we would double the p-value.Conversely, going from a 2-sided to a 1-sided we would cut the p-value in half. Points Earned 1. 0/1. 0 Correct Answer(s) D 23. A shopper wanted to test whether there was a difference in the average waiting terms at the check-out counter among 5 different supermarkets. She selected a random sample of 20 shoppers from each of the five supermarkets. What is the alternative hypothesis for this office staff? A)The average waiting time to check out is 25 minutes for all five supermarkets. B)The average waiting time to check out is the same for all five supermarkets.C)The average waiting time for each of the 100 shoppers is different. D)The average waiting time to check out is not the same for all five supermarkets. FeedbackThe alternative hypothesis for an ANOVA test is that all the means are not the same, i. e. the means are not all equal. Points Earned 1. 0/1. 0 Correct Answer(s) D 24. Which one of the following choices describes a problem for which an analysis of variance would be appropriate? A)Comparing the proportion of successes for three different treatments of anxiety. Each treatment is tried on 100 patients.B)Analyzing the kinship between high school place point average and college GPA. C)Comparing the mean birth weights of newborn babies for three different racial groups. D)Analyzing the relationship between gender and judging about capital punishment (favor or oppose). FeedbackThe dependent (response) variable needs to be round-the-clock and the different levels of the independent variable need to be mutually exclusive and categorical. This leads to the correct answer of mean birth weights (continuous response) across three racial groups (mutually exclusive, categorical). Points Earned 0. /1. 0 Correct Answer(s) C 25. A study compared grade point averages (GPA) for students in a class students were divided by 6 locations where they usually sit down during lecture (i. e. left or right front, left or right center, left or right rear). A total sample size of 12 students was studied (2 students from each section) using one-way analysis of variance. What are the numerator and denominator degrees of freedom for the ANOVA F-test? A)6 for numerator and 12 for denominator. B)5 for numerator and 11 for denominator. C)5 for numerator and 6 for denominator.FeedbackThe numerator degrees of freedom are found by taking the number of group levels minus 1 (this case 6 ? 1 = 5) and the denominator degrees of freedom are found by taking the total sample size minus the number of group levels (12 ? 6 = 6) Points Earned 0. 0/1. 0 Correct Answer(s) C 26. A study compared testosterone levels among athletes in four sports soccer, track, Lacrosse, and water polo. The total sample size was n =30 (10 soccer, 10 track, 5 Lacrosse, and 5 water polo). A one-way analysis of variance was used to compare the population mean levels for the four sports.The sum of squared errors is SS Error = 100. What is the value of the Mean Square Error (MS Err or)? A)10 B)3. 45 C)3. 85 FeedbackThe MS Error is equal to the SS Error divided by the Error degrees of freedom (which are equal to the total sample size minus the number of group levels 30 ? 4 = 26). on that pointfore, the answer is 100/26 = 3. 85 Points Earned 1. 0/1. 0 Correct Answer(s) C 27. On a survey conducted at a university, students were asked how they felt about their weight (about right, overweight, or underweight), and also were asked to record their grade point average (GPA).There were 235 responses, with 160 saying their weight was about right, 50 said they were overweight, and 17 underweight. The question of interest is whether mean GPA is the same or differs for different weight attitude populations. The test F-statistic value is 4. 98. The p-value of 0. 008 is found by calculating A)the area to the right of 4. 98 under an F-distribution with 2 and 232 degrees of freedom. B)the area to the right of 4. 98 under an F-distribution with 2 and 234 degrees of freedom. C )the area to the right of 4. 98 under an F-distribution with 2 and 231 degrees of freedom.FeedbackThe p-value is the probability of be greater than the F-statistic or simply the area to the right of the F-statistic with the corresponding degrees of freedom for the group (number of group levels minus 1, or 3 ? 1 = 2) and error (total sample size minus the number of group levels, or 235 ? 3 = 232) Points Earned 1. 0/1. 0 Correct Answer(s) A 28. Ninety people with high cholesterol are randomly divided into three groups of thirty, and a different treatment program for decreasing cholesterol is assigned to each group.The response variable is the change in cholesterol level after two months of treatment. An analysis of variance will be used to compare the three treatments. What null hypothesis is tried and true by this ANOVA F-test? A)The sample variances are equal for the three treatment groups. B)The population variances are equal for the three treatments. C)The sample means are eq ual for the three treatment groups. D)The population means are equal for the three treatments FeedbackThe null hypothesis for an ANOVA test is that all population means are equal. Points Earned 0. 0/1. 0 Correct Answer(s) D 29.A study done by the Center for pedantic Integrity at Rutgers University surveyed 2116 students at 21 colleges and universities. Some of the schools had an honor code and others did not. Of the students at schools with an honor code, 7% reported having plagiarized a paper via the Internet, while at schools with no honor code, 13% did so. (Sacramento Bee, Feb 29, 2000, D1. ) For this study, which of the following statements about percent gain in take a chance is correct? A)There is a 185. 7% increase in the risk of plagiarism at a school with no honor code, compared to a school with an honor code. B)There is an 85. % increase in the risk of plagiarism at a school with no honor code, compared to a school with an honor code. C)There is a 53. 8% increase in the risk of plagiarism at a school with no honor code, compared to a school with an honor code. D)There is a 6% increase in the risk of plagiarism at a school with no honor code, compared to a school with an honor code. FeedbackThe part increase is found by taking the difference in risks between one group minus the service line and then dividing this difference by the baseline risk. Here the answer that makes sense is one using the with honor as the baseline.Doing so produces (13%-7%)/7% = 85. 7% increase in plagiarism from with honor to without honor. Points Earned 1. 0/1. 0 Correct Answer(s) B 30. Which of the following variablesCOULDbe used in a Chi-Square analysis? A)Gender B)Political Party crosstie C)Race D) shape up E)Course Section Number F)All of the above FeedbackAll are feasible as you could categorize age. Points Earned 1. 0/1. 0 Correct Answer(s) F 31. A survey looked at the cerebrations of 321 respondents from the General Social Survey by whether they owned a crap- shooterslinger (or not) and whether they favored (or opposed) a natural justness requiring a leave to own a hero.What is the correctnullhypothesis for this survey? A)There isnorelationshipin the populationbetween gun self-command and suasion regarding gun law permit B)There isnorelationshipin the samplebetween gun ownership and faith regarding gun law permit C)Thereisa relationshipin the populationbetween gun ownership and vista regarding gun law permit D)Thereisa relationshipin the samplebetween gun ownership and opinion regarding gun law permit FeedbackThere isnorelationshipin the populationbetween gun ownership and opinion regarding gun law permit Points Earned 1. /1. 0 Correct Answer(s) A 32. Based on the National Household Survey on Drug Abuse, the percentage of 17-year olds who ever tried cigarette smoking is 56. 2%. The relative risk of ever smoking for a 17-year old versus a 12-year old is 3. 6. What is the risk of smoking for a 12-year-old (i. e. what was the percen tage of 12-year olds who ever tried smoking)? A)14. 1% B)15. 6% C)50. 0% D)56. 2% FeedbackYou need to use algebra to solve Relative risk (3. 6) = one group of interest (17 year olds who tried smoking = 56. %) divided by another group of interest (12 year olds who tried smoking and is unknown). Solving for the unknown comes to (3. 6)*(0. 562) = 0. 156 or 15. 6% Points Earned 1. 0/1. 0 Correct Answer(s) B 33. A survey examined the opinions of 321 respondents from the General Social Survey by whether they owned a gun (or not) and whether they favored (or opposed) a law requiring a permit to own a gun. What is the correctalternativehypothesis for this survey?A)There isnorelationshipin the populationbetween gun ownership and opinion regarding gun law permit B)There isnorelationshipin the samplebetween gun ownership and opinion regarding gun law permit C)Thereisa relationshipin the populationbetween gun ownership and opinion regarding gun law permit D)Thereisa relationshipin the samplebe tween gun ownership and opinion regarding gun law permit FeedbackThereisa relationshipin the populationbetween gun ownership and opinion regarding gun law permit Points Earned 1. 0/1. 0 Correct Answer(s) C 34. A survey examined the opinions of 1447 respondents in the General Social Survey to the question Do you favor or oppose the death penalty for persons convicted of cut up? The purpose of examining the data is to see if there is a gender difference in how people would respond to this question. State thenullhypotheses for this study. A)There isnorelationshipin the populationbetween gender and opinion on the death penalty. B)There isnorelationshipin the samplebetween gender and opinion on the death penalty.C)Thereisa relationshipin the populationbetween gender and opinion on the death penalty. D)Thereisa relationshipin the samplebetween gender and opinion on the death penalty. FeedbackThe null hypothesis speaks of no relationship between the variables in the population. Points Ea rned 1. 0/1. 0 Correct Answer(s) A 35. A regression was done for 20 cities with latitude as the informative variable (x) and average January temperature as the response variable (y). The latitude is measured in degrees and average January temperature in degrees Fahrenheit.The latitudes ranged from 26 (Miami) to 47 (Duluth) The regression equation is * y = 49. 4 0. 313x The city of Miami, Florida has latitude 26 degrees with average January temperature of 67 degrees Fahrenheit. 1. What is the estimated average January temperature for Miami, and2. based on the regression equation, what is the residual? A)Estimated January temperature is 36. 88 and the residual is 11. 88 B)Estimated January temperature is 36. 88 and the residual is 11. 88 C)Estimated January temperature is 41. 3 and the residual is 25. D)Estimated January temperature is 41. 3 and the residual is 25. 7 FeedbackThe estimated January temperature is 41. 3 degrees Fahrenheit. The residual is 25. 7 degrees (residual = observed minus predicted) Points Earned 0. 0/1. 0 Correct Answer(s) D 36. Which of the following correlational statisticss indicates a stronger elongated relationship between two variables? A) 0. 90 B)0. 75 C)0. 50 D)1. 25 FeedbackThe correct answer is -0. 90. render that thevalueof the correlation indicates the strength and this value cannot be less than 1 nor greater than + 1 (thus belief out 1. 5 as an answer). The negative sign just indicates the direction of the relationship (positive or negative) and has no bearing on the strength of the relationship. Points Earned 1. 0/1. 0 Correct Answer(s) A 37. What is the effect of an outlier on the value of a correlation coefficient? A)An outlier will unendingly decrease a correlation coefficient. B)An outlier will always increase a correlation coefficient. C)An outlier might either decrease or increase a correlation coefficient, depending on where it is in relation to the other points.D)An outlier will have no effect on a correl ation coefficient. FeedbackSee the lecture notes Points Earned 1. 0/1. 0 Correct Answer(s) C 38. A group of adults aged 20 to 80 were tested to see how far away they could first hear an ambulance approaching towards them. An equation describing the relationship between distance (in feet) and age was found to be * Distance = 600 3 ? Age Based on the equation, what is the direction of the association between distance and age? A)Positive B)Negative C)ZeroD) explosive charge cant be determined from the equation. FeedbackThe direction of an association can be ascertained by considering the sign of the slope. Since the slope is negative then so is the association. Points Earned 1. 0/1. 0 Correct Answer(s) B 39. Past data has shown that the regression line relating the final exam differentiate and the midterm exam score for students who take statistics from a certain professor is * final exam = 50 + 0. 5 ? midterm For a student with a midterm score of 50, the predicted final exam scor e is A)50.B)50. 5. C)75. D)100. Points Earned 1. 0/1. 0 Correct Answer(s) C 40. Which of the following is a possible values of R2indicates the strongest linear relationship between two quantitative variables? A)-90% B)0% C)80% D)120% FeedbackRemember that the range of R2is from 0 to 100%. Thus 80% would indicate the strongest linear relationship, i. e. correlation, based on the square gouge of 0. 8 is greater than the square root or 0. Points Earned 1. 0/1. 0 Correct Answer(s) C Bottom of Form