Question

The mean diastolic blood pressure for a random sample of people was millimeters of mercury. If the standard deviation of individual blood pressure readings is known to be millimeters of mercury, find a confidence interval for the true mean diastolic blood pressure of all people. Then give its lower limit and upper limit.

Answer 1

(85.62, 90.38).

Explanation:

The missing data can be assumed to be we have the following information:

¯x =88, s=10, n=70

Substituting the values in the following formula, we compute the 95% C.I for true population mean diastolic pressure as shown below:

95% C.I.=¯x±t(0.95,n−1)⋅Sm=¯x±t(0.95,70−1)⋅s√n=88±1.99⋅10√70=(85.62,90.38)

The answer is (85.62, 90.38).