The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 72.5 for a sample of size 25 and standard deviation 9.3. Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 80% confidence level). Assume the data is from a normally distributed population. Enter your answer as a tri-linear inequality accurate to three decimal places. ____ < μ < ____
The effectiveness of a blood-pressure drug is being investigated. An experimenter finds that, on average, the reduction in systolic blood pressure is 72.5 for a sample of size 25 and standard deviation 9.3. Estimate how much the drug will lower a typical patient's systolic blood pressure (using a 80% confidence level). Assume the data is from a
Enter your answer as a tri-linear inequality accurate to three decimal places.
____ < μ < ____
From the given information,
Sample size n =25
Sample mean, x̅=72.5
Sample standard deviation, s=9.3
Confidence level = 80%
Degrees of freedom: 24(=25-1).
Using Excel function, “=T.INV.2T(0.20,24)”, the critical value for two-tailed test at 80% confidence level is ±1.3178.
The standard error is:
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