Question

Show Intro/Instruction The effectiveness of a blood pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 48.4 for a sample of size 27 and standard deviation 9.8. Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 98% confidence level). Assume the data is from a normally distributed population. Enter your answer as a tri-linear inequality accurate to three decimal places. <HT Get Help: Points possible: 1 This is attempt 2 of 2. Score on last attempt: (0,0), Score in gradebook: (0,0), Out of: (0.5, 0.5) Submit 2020 XYZ Homework I Privacy Policy I ADA Compliance PDF Contact Us xyzHomework is powered by MathAS 2006-2020 by David Lippman

Answer 1

We have

n = 27

xbar = 48.4

s = 9.8

The 98% confidence interval for population mean $\mu$ is

xbar - E < $\mu$ < xbar + E

Where E = t_{​​​​​​a/2}*(s/√n)

For a = 0.02 , d.f = n -1 = 26

t_{​​​​​​a/2 , n -1} = t_{​​​​​​0.01 , 26} = 2.479

E = 2.479*(9.8/√27) = 4.675

48.4 - 4.675 < $\mu$ < 48.4 + 4.675

43.725 < $\mu$ < 53.075