Math 207
Homework Assignment 7
Due Wednesday,
November 17 (beginning of class)
REMINDER: As mentioned on previous homework assignments, I expect your
homework solutions to be thorough, well-written (use context and complete
sentences), neat, complete (thoughtfully answer all parts of the question),
stapled, and in your own words/explanations (re: Honor Code).
IMPORTANT NOTES:
- Be sure to explicitly do appropriate
sample-size checks before you use a large-sample confidence interval or
significance test.
- When performing a significance test, use
the p-value approach (not the critical-value approach). Also, interpret
your results in words that anyone (not just someone taking this class)
would understand—interpret the p-value and provide a conclusion in words
using the context of the problem.
Textbook Problems
to be Turned In:
9.8 (use 5%
significance level)
9.23
9.46
Extra problem:
The
medical director of a large company is concerned about the effects of stress on
the company’s younger executives. According to the National Center of Health
Statistics, the average systolic blood pressure for males 35 to 44 years of age
is 128 mm Hg. The director suspects the average systolic blood pressure for the
company’s young male executives is higher than the national average. Testing at
the 0.05 significance level, the director wants to detect a true mean blood
pressure of 133 mm Hg with a power of 0.8. That is, the director wants the
power of the test to be 0.8 when the mean blood pressure is really 133 mm Hg.
How large of a sample should the director take? (Assume that the standard
deviation of the blood pressures for young male executives at the company is
15.)
Textbook Problems
for Exam Preparation (not to be turned in):
10.9 (only part a) [
, 
, and the sample
data distribution is mound-shaped (this can be easily seen from a histogram in
Minitab)]
10.26
10.41 [mean and
standard deviation of the (Prohibitive – Permissive) differences: 106.900
milliseconds and 36.946 milliseconds, respectively; the distribution of sample
differences is somewhat skewed left (this can be easily seen from a histogram
in Minitab)]
10.88 [mean and standard deviation of the (Initial
Weight – Final Weight) differences: 42.125 lbs. and 7.511 lbs., respectively;
the distribution of sample differences is slightly skewed right (this can be
easily seen from a histogram in Minitab)]
10.100 (use 5% significance level)