Some bored researchers got the idea that they could predict a person’s pulse rate from his or her
height (earlier studies had shown a very weak linear relationship between pulse rate and weight).
They collected data on 20 college-age women. The following table is part of the Minitab output of
their findings.
a. Determine the t -ratio and the P -value for the test.
b. Construct a 99% confidence interval for the slope of the regression line used to predict pulse rate
from height.
c. Do you think there is a predictive linear relationship between height and pulse rate? Explain.
d. Suppose the researchers were hoping to show that there was a positive linear relationship
between pulse rate and height. Are the t -ratio and P -value the same as in Part (a)? If not, what
are they?
Cumulative Review Problems
You are testing the hypothesis H 0 : p = 0.6. You sample 75 people as part of your study and calculate
that = 0.7.
a. What is s for a significance test for p ?
b. What is s for a confidence interval for p ?
- A manufacturer of lightbulbs claims a mean life of 1500 hours. A mean of 1450 hours would
represent a significant departure from this claim. Suppose, in fact, the mean life of bulbs is only 1450
hours. In this context, what is meant by the power of the test (no calculation is required)? - Complete the following table by filling in the shape of the sampling distribution of for each
situation.