Question

The National Center for Health Statistics reports that the systolic blood pressure for all males 35-44 years old has a mean of 122 and a standard deviation of 12. The medical director of a very large company looks at the medical records of 100 randomly selected male executives in this age group and finds that the mean systolic blood pressure in this sample is x̄=128.4, with a standard deviation of 8.

A. What is the mean of the sampling distribution of x̄? Do not round your answer.

B. What is the standard deviation of the sampling distribution of x̄? Do not round your answer.

C. What is the shape of the sampling distribution of x̄? Type N for Normal, S for Skewed, or I for Impossible to Determine.

Answer 1

Solution :

Given that,

mean = = 122

standard deviation = = 12

n = 100

A) mean = =   = 122

B) standard deviation = = / n = 12 / 100 = 1.2

C) The shape of the sampling distribution of is N