Question

1. The mean age of College students is 25. A certain class of 33 students has a mean age of 22.64 years. Assuming a population standard deviation of 2.87 years, at the 5% significance level, do the data provide sufficient evidence to conclude that the mean age of students in this class is less than the College mean?

a. Set up the hypotheses for the one-mean ?-test. ?0:    ??:

b. Compute the test statistic. Round to two decimal places.

c. Sketch a normal curve, mark your value from part (b), and shade in the area(s) we are interested in. Determine the ?-value.

d. Determine if the null hypothesis should be rejected.

e. Interpret your result in the context of the problem in a sentence.

A study examined the effects of an intervention program to improve the conditions of urban bus drivers. Among other variables, the researchers monitored diastolic blood pressure of bus drivers in a large city. The data, in millimeters of mercury (mm Hg), are based on the blood pressures obtained prior to intervention for the 41 bus drivers in the study. At the 10% significance level, do the data provide sufficient evidence to conclude that the mean diastolic blood pressure of bus drivers in the city exceeds the normal diastolic blood pressure of 80 mm Hg? The mean of the data is ? = 81.95122 mm Hg, and the standard deviation of the data is ? = 10.537911 mm Hg.

a. Set up the hypotheses for the one-mean ?-test. ?0:   ??:   

b. Compute the test statistic. Round to two decimal places.

c. Sketch a ?-curve, mark your value from (b), and shade in the area(s) we are interested in. Determine the ?- value.

d. Determine if the null hypothesis should be rejected.

e. Interpret your result in the context of the problem in a sentence.

Answer 1