Text references are to Montgomery & Runger, Applied Statistics and Probability for Engineers, 2nd edition.
1. Figure 9.4 on page 411 is inaccurate and misleading. Draw it correctly.
2. How many independent observations are needed to ensure that the upper limit of a 95% confidence interval for the variance of a normal population is no more than 4 times its lower limit?
3. Ten patients were given a drug intended to reduce diastolic blood pressure, which was recorded before and after treatment. Compute a P-value to help determine if treatment was effective. State your assumptions and conclusions.
Patient:
1
2
3
4
5
6
7
8
9
10
Before:
120
125
131
115
100
105
117
93
112
116
After:
116
123
140
108
91
103
102
109
111
113
4. Ten patients were given a drug intended to reduce diastolic blood pressure, but the only information you are given is that diastolic blood pressure dropped in 8 out of the 10 patients. Compute a P-value to help determine if treatment was effective. State your assumptions and conclusions. Which analysis is the more valid, this or the t-test in Question 3? [Hint: What is the distribution of the number of patients with reduced diastolic blood pressure, under the null hypothesis? Follow the definition of P-value exactly.]
Problems from the text.
8-39
9-18 (d), 9-19*, 9-36, 9-52
10-12, 10-27
* In 9-19, do stem-and-leaf plots and a comparative box plot instead of probability plots, and do an F-test to compare the variances.