Part A -
1. Using the data in the file named Chapter 11 Data Set 2, test the research hypothesis at the .05 level of significance that males raise their hands in class more often than females. Do this practice problem by hand using a calculator. What is your conclusion regarding the research hypothesis? Remember to first decide whether this is a one-or two-tailed test.
2. Using the same data set (Chapter 11 Data Set 2), test the research hypothesis at the .01 level of significance that there is a difference between males and females in the number of times they raise their hands in class. Do this practice problem by hand using a calculator. You use the same data for this problem as for Question 1, but you have a different hypothesis (one is directional and the other is non- directional). What is your conclusion regarding this research hypothesis? How do the results differ, and why?
3. Using the data in the file named Chapter 11 Data Set 3, test the null hypothesis that urban and rural residents have the same attitudes toward gun control. Use the T.TEST function to test the hypothesis. Assume that the variance from each group is equal.
4. For your Friday afternoon report to the boss, you need to let her know if the two stores in Newark, New Jersey (your author's fair city of origin), are selling the same amount of merchandise each week on average or a different amount. Use the data in the file named Chapter 11 Data Set 4 and the Data Analysis tools to let her know. Better hurry.
5. During the last football season, the Brutes managed to gain an average of 203 yards per game while their opponents averaged 288 yards per game. Fire the coach? Use the data in Chapter 11 Data Set 5 to make that decision.
6. What would it mean if a difference were statistically significant but the effect size were not meaningful?
Part B -
1. What is the difference between a test of independent means and a test of dependent means, and when is each appropriate?
2. For Chapter 12 Data Set 1, compute the t value using the Data Analysis tools and write a conclusion as to whether there was a change in tons of paper used as a function of the recycling program in 25 districts. (Hint: Before and after become the two levels of treatment.) Test the hypothesis at the .01 level.
3. In the following examples, indicate whether you would perform a t-test of independent means or dependent means.
a. Two groups were exposed to different levels of treatment for ankle sprains. Which treatment was more effective?
b. A researcher in nursing wanted to know whether patients who received additional in-home care recovered more quickly than others who received the standard amount of in-home care.
c. A group of adolescent boys was offered interpersonal skills counseling and then tested in September and May to see if there was any impact on family harmony.
d. One group of adult men was given instructions for reducing their high blood pressure whereas another group was not given any instruction, and the blood pressure of men in both groups was measured before and after.
4. For Chapter 12 Data Set 2, compute the t value (do it manually argh!) and write a conclusion as to whether there was a change in a group of families' satisfaction level (the higher the score, the more satisfied) with their use of service centers following a social service intervention. Then do this exercise using Excel and report the exact probability of the outcome.
5. Here's a tough one. For the same data where two groups are being compared, the critical value for rejection of the null hypothesis is higher for a set of dependent groups than for a set of independent groups. Why?
6. Ace used-car sales manager Jack has no idea whether the $100,000 he pays for training for his used-car salespeople works. He asks Dave, the leading salesperson, and Dave says he thinks it works but can't really tell. So, Jack has hired your local helpful stats star and asked whether the training makes a difference. Here are the data, you tell Jack whether the training worked.
7. Use the data from Chapter 12 Data Set 3 to see whether counseling adolescents at the beginning of the school year had a positive impact on their tolerance for other adolescents who are ethnically different from them. Assessments were made right before the treatment and then 6 months later. Did the program work? The outcome variable is score on a test of attitudes toward others, with possible scores ranging from 0 to 50; the higher the score, the more tolerance. Perform the analysis any way you want!
8. In the data set named Chapter 12 Data Set 4, a comparison is shown between yards rushing for the first and last games of the season for 10 different football teams. Which team is best? And, yes, this is a trick question-can you find the trick?
Attachment:- Assignment File.rar