Question

The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 84.5 mmHg (millimeters of mercury) for a sample of size 742 and a sample standard deviation 9.9 mmHg. How much of mmHg will lower for a typical patient's systolic blood pressure after taking the drug? Estimate with a 98% confidence.

Preliminary:

1. Is it safe to assume that n≤5%n≤5% of all patients with a systolic blood pressure?
   • No
   • Yes
   
   
2. Is n≥30n≥30 ?
   • No
   • Yes

Confidence Interval:What is the 98% confidence interval to estimate the population mean? Round your answer to one decimal place.

< μμ <

Answer 1

Yes, it is safe to assume that n ≤ 5% of all patient with a systolic blood pressure because the population will have a very number of patients with a systolic blood pressure

Yes, n ≥ 30 since n = 742

Mean, = 84.5 mmHg

Standard deviation, = 9.9 mmHg

Corresponding to 98% confidence, the critical z value = 2.327

Margin of error = = 0.846

The confidence interval:

->

->

-> mmHg