Some of the questions in Part A require you to consult Statistics for People Who (Think They) Hate Statistics. This information is accessible via the Student Text Resources link on the student website.




Test the research hypothesis at the using the data in the file named Ch. 11 Data Set 2.




Boys raise their hands in class more frequently than girls, according to a 05 level of significance. Use a calculator to solve this practice problem by hand. What is your opinion on the research hypothesis? Remember to decide whether this is a one-tailed or two-tailed test first.


Using the same data set (Ch. 11 Data Set 2), test the research hypothesis that there is a difference in the number of times boys and girls raise their hands in class at the.01 level of significance. Use a calculator to solve this practice problem by hand. What is your opinion on the research hypothesis? You used the same data for this problem as you did for Question 1, but your hypothesis is different (one is directional and the other is nondirectional). How and why do the outcomes differ?




Try solving the following problems by hand to see if you can get the numbers correct. Calculate the t test statistic using the following data.








What are the two-tailed critical values associated with each based on the results of Question 3 and a level of significance of.05? Would the null hypothesis be rejected?


Using the data in the file named Ch. 11 Data Set 3, test the null hypothesis that urban and rural residents both have the same attitude toward gun control. Use IBM® SPSS® software to complete the analysis for this problem.




A public health researcher tested the hypothesis that providing new car buyers with child safety seats will also act as an incentive for parents to take other measures to protect their children (such as driving more safely, child-proofing the home, and so on). Dr. L counted all the occurrences of safe behaviors in the cars and homes of the parents who accepted the seats versus those who did not. The findings: a significant difference at the .013 level. Another researcher did exactly the same study; everything was the same—same type of sample, same outcome measures, same car seats, and so on. Dr. R’s results were marginally significant (recall Ch. 9) at the .051 level. Which result do you trust more and why?




In the following examples, indicate whether you would perform a t test of independent means or dependent means.



Two groups were exposed to different treatment levels for ankle sprains. Which treatment was most effective?

A researcher in nursing wanted to know if the recovery of patients was quicker when some received additional in-home care whereas when others received the standard amount.

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.

One group of adult men was given instructions in reducing their high blood pressure whereas another was not given any instructions.

One group of men was provided access to an exercise program and tested two times over a 6-month period for heart health.



For Ch. 12 Data Set 3, compute the t value and write a conclusion on whether there is a difference in satisfaction level in a group of families’ use of service centers following a social service intervention on a scale from 1 to 15. Do this exercise using IBM® SPSS® software, and report the exact probability of the outcome.


Do this exercise by hand. A famous brand-name manufacturer wants to know whether people prefer Nibbles or Wribbles. They sample each type of cracker and indicate their like or dislike on a scale from 1 to 10. Which do they like the most?