Assignment:
Statistical aptitude scores are known to be normally distributed, with mean = 50. A researcher has designed a new program intended to improve students statistical aptitude, and has enrolled a sample of 30 students in it. The researcher then collects students statistical aptitude scores at the end of the program.
1. What type of hypothesis test should be performed to determine whether the new program is effective
2. How many degrees of freedom are there for this test?
3. What is the null hypothesis in notation (pay attention to whether the hypothesis should be directional or nondirectional).
4. What is the appropriate critical value (a = .05), based on your hypothesis?
5. If the test statistic is calculated and found to be 1.71, what is the appropriate decision with regard to the null hypothesis?
A researcher has developed a new treatment to reduce high blood pressure. A random sample of 15 people suffering from high blood pressure were given the new treatment, and a second sample of 15 were matched on initial blood pressure readings with the first group, and then given a placebo. Below are the blood pressure scores of the two groups.
Treatment No Treatment
6 6
5 5
7 6
4 7
3 8
9 9
5 5
6 7
3 8
2 4
1 9
5 9
3 8
5 6
6 10
6. What is the dependent variable?
7. Perform an appropriate analysis to determine whether the new treatment reduces high blood pressure (include all steps). Use α = .05. Use SPSS/PASW to perform the analysis
8. Write a sentence in APA style regarding the results of this study. Make sure you include your descriptive and inferential statistics).
9. Using SPSS, construct the 90% confidence interval for the population mean difference of high blood pressure with and without treatment, whether it is appropriate or not.
10. Interpret your confidence interval, that is, report the results of your estimation in a sentence. Hint: do not use the confidence interval to interpret the hypothesis test, rather, interpret the interval itself.