Question

The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 72.9 for a sample of size 795 and standard deviation 14.3. Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 95% confidence level). Enter your answer as a tri-linear inequality accurate to one decimal place (because the sample statistics are reported accurate to one decimal place).

Answer 1

n= 795,   = 72.9 , s= 14.3

c= 95%

formula for confidence interval is

Where tc is the t critical value for c=95% with df=n-1 = 795-1 = 794

using t table we get critical value as

tc = 1.963

71.904 <    < 73.896

round it to 1 decimal places.

71.9 <    < 73.9

answer with tri-linear inequality is as follows,

71.9 <    < 73.9