Question

The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 42 for a sample of size 32 and standard deviation 16.

Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 80% confidence level).

Give your answers to one decimal place and provide the point estimate with its margin of error.

_____________________ ±_________________

Answer 1

Given:

Sample size = n = 32

Point estimate = Sample mean = = 42

Standard deviation = s = 16

Significance level = = 1-0.80 = 0.20

At 80% confidence level, the critical value of Z is

Therefore the drug will lower a typical patient's systolic blood pressure is 38.4