explain the mean of the interval in a sentence

Question

The effectiveness of a blood pressure drug in being investigated.An experiment finds that on average the reduction in systolic blood pressure is 57.6 for a sample of size 846 and standard deviation 5.2 estimate how much the drug will lower a typical patient systolic blood pressure using a 90% confidence level explain the mean of the confidence interval in a sentence

Answer 1

CI = mean +/- z-critical * standard deviation/square root(sample size)

mean = 57.6

z-critical for 90% CI is 1.645

standard deviation = 5.2

sample size = 846

CI = 57.6 +/- 1.645 * 5.2/sqrt(846) = 57.6 +/- 2.94 = 54.66, 60.54