# ECN 221-Description Homework covers topics related to hypothesis

2016/11/11 Take Test: F16 Homework 10: (Hypothesis Tests for Two Means) &… Take Test: F16 Homework 10: (Hypothesis Tests forTwo Means) Test InformationDescription Homework covers topics related to hypothesis testing with two populations. Instructions Choose or provide the best answer. Multiple Attempts Not allowed. This test can only be taken once.Force Completion This test can be saved and resumed later. Question Completion Status: Save All Answers Q U EST I O N 1 Close Window Save and Submit 1.2 points Save Answer Consider two classes of business statistics. Suppose that average test score for the first class is81 and the average test score for the second class is 78.4. What is the point estimate for thedifference in the mean test scores? Answer to as many decimal places as necessary. Q U EST I O N 2 1.2 points Save Answer Consider two classes of business statistics. Suppose that average test score for the first class is81 and the average test score for the second class is 84.8. What is the point estimate for thedifference in the mean test scores? Answer to as many decimal places as necessary. Q U EST I O N 3 1.2 points Save Answer You are going to test a hypothesis concerning the difference between two population means. Oneof the steps to do this is to find the standard error. Suppose you have two samples with 50observations each and standard deviations of 78.2 and 67.1. What is the standard error? Answerto two decimal places. Q U EST I O N 4 1.2 points Save Answer You are going to test a hypothesis concerning the difference between two population means. Oneof the steps to do this is to find the standard error. Suppose you have two samples with 40observations each and standard deviations of 73.5 and 108.9. What is the standard error? Answer to two decimal places. https://myasucourses.asu.edu/webapps/assessment/take/launch.jsp?course_assessment_id=_742210_1&course_id=_334341_1&content_id=_13633504_1… 1/5 2016/11/11 Take Test: F16 Homework 10: (Hypothesis Tests for Two Means) &… Q U EST I O N 5 1.2 points Save Answer You are going to test a hypothesis concerning two means where the null hypothesis involves adifference of 0. Suppose that your two sample means are 20.2 and 33.8 while the estimatedstandard error is 3.5. What is the test statistic? Answer to two decimal places. Q U EST I O N 6 1.2 points Save Answer You are going to test a hypothesis concerning two means where the null hypothesis involves adifference of 0. Suppose that your two sample means are 58 and 40.5 while the estimatedstandard error is 5. What is the test statistic? Answer to two decimal places. Q U EST I O N 7 1.5 points Save Answer Suppose that the average weekly wage for women in the US is around $740 (see BLS report) whilethe average weekly wage for men is around $900. Suppose that the respective sample sizes are1000 each and the standard deviations are $300 and $450. To test for the equality of the wagesfor the two populations what is the test statistic? Answer to two decimal places. Hint: yournumber should be negative. Q U EST I O N 8 1.2 points Save Answer Consider the previous problem where the average wage for women was $740 and for men it was$900 and you found a test statistic. Suppose you conduct your hypothesis test with a .05 level ofsignificance. True or false: You reject the null hypothesis of equality. True False Q U EST I O N 9 1.2 points Save Answer In a paper by Lavy and Sand the authors investigate whether teachers are biased in how theygrade students (among other things). You can find the paper here or publicly available on theinternet here (unless the author has moved it). Read up to “Identification and Estimation” on page11. The tests that the students take for which some results are reported in their Table 2 weretaken in which grade?3rd grade.5th and 6th.7th and 8th.9th.11th. Q U EST I O N 1 0 1.2 points Save Answer In a paper by Lavy and Sand (available here, again read to page 11) the authors suggest thatteachers have a favorable bias for boys in https://myasucourses.asu.edu/webapps/assessment/take/launch.jsp?course_assessment_id=_742210_1&course_id=_334341_1&content_id=_13633504_1… 2/5 2016/11/11 Take Test: F16 Homework 10: (Hypothesis Tests for Two Means) &… teachers have a favorable bias for boys inEnglish.Math.Hebrew.Chemistry.English, Hebrew, and math. Q U EST I O N 11 1.2 points Save Answer In a paper by Lavy and Sand (available here, again read to page 11) the authors report somesummary statistics on test scores, see Table 2 in the paper. In the paper the test scores areconverted to and reported aspercentiles.t scores.z scores.gradient scores.matriculation scores. Q U EST I O N 1 2 1.2 points Save Answer Looking at Table 2 in the Lavy and Sand paper what is the point estimate for the difference in boysand girls “School Score Exams” for Hebrew? Answer to 3 decimal places. Report your number asa positive value. Q U EST I O N 1 3 1.5 points Save Answer Looking at Table 2 in the Lavy and Sand paper what is the point estimate for the difference in boysand girls “School Score Exams” for Hebrew you found a point estimate for the difference in theprevious question. In order to test the hypothesis that the average scores are the same for boysand girls you will also need to calculate the standard error. Assume that the standard deviationsare 1 for both boys and girls and that there are 4000 boys and 4000 girls? those number are slightlydifferent from in the paper but close so use the numbers I just gave you. What is the standarderror? Answer to 4 decimal places. Q U EST I O N 1 4 1.5 points Save Answer Now use the point estimate of the difference in boys and girls scores (using a positive value) andthe standard error you just calculated to find a test statistics to test the hypothesis that boys andgirls score the same on Hebrew exams. What is the test statistic? Answer to 1 decimal placeand make sure your number is positive (if you found the point estimate of the difference as anegative value then just take the absolute value). https://myasucourses.asu.edu/webapps/assessment/take/launch.jsp?course_assessment_id=_742210_1&course_id=_334341_1&content_id=_13633504_1… 3/5 2016/11/11 Take Test: F16 Homework 10: (Hypothesis Tests for Two Means) &… Q U EST I O N 1 5 1.3 points Save AnswerGiven the correct test statistic you found in the previous problem you reject the null hypothesisthat boys and girls have the same average score on Hebrew tests using a .05 level ofsignificance. True False Q U EST I O N 1 6 1.2 points Save Answer Hypothesis testing and specifically hypothesis testing for the difference in two means can beuseful when investigating whether two populations are being treated equally or performing equallyand such questions do arise in business (comparing two production processes), public policy(comparing outcomes of social programs) and legal settings (such as in discrimination cases). True False Q U EST I O N 1 7 1.2 points Save Answer For a given standard error, the larger the difference between two point estimates the greater the pvalue for a test of the equality of means. (Hint, try it with two sets of numbers and the samestandard error and see which one has the larger pvalue then look at it to see if that was acoincidence or if that will always be the case). True False Q U EST I O N 1 8 1.2 points Save Answer The test statistic for a hypothesis test concerning the equality of two means when the standarddeviations are known and the samples are independent with more than 30 observations eachfollows which distribution?tzFChi square Q U EST I O N 1 9 1.2 points Save Answer The test statistic for a hypothesis test concerning the equality of two means when the populationstandard deviations are not known and the samples are independent with more than 30observations each follows which distribution?tzFChi square https://myasucourses.asu.edu/webapps/assessment/take/launch.jsp?course_assessment_id=_742210_1&course_id=_334341_1&content_id=_13633504_1… 4/5 2016/11/11 Take Test: F16 Homework 10: (Hypothesis Tests for Two Means) &… Q U EST I O N 2 0 1.2 points Save Answer The test statistic for a hypothesis test concerning the equality of two means when the populationstandard deviations are not known and the samples are matched (or paired) follows whichdistribution?tzFChi square Click Save and Submit to save and submit. Click Save All Answers to save all answers. Save All Answers Close Window Save and Submit https://myasucourses.asu.edu/webapps/assessment/take/launch.jsp?course_assessment_id=_742210_1&course_id=_334341_1&content_id=_13633504_1… 5/5