Math 156
posted by Emory on .
The systolic blood pressures of the patients at a hospital are normally distributed with a mean of
136 mm Hg and a standard deviation of 13.4 mm Hg. Find the two blood pressures having these
properties: the mean is midway between them and 90% of all blood pressures are between them.
A) 123.9 mm Hg, 148.1 mm Hg
B) 118.8 mm Hg, 153.2 mm Hg
C) 114 mm Hg, 158 mm Hg
D) 115 mm Hg, 159 mm Hg
Is the answer B?

Can some one give me some hints please..

The answer isn't even in your options; the correct answer is 119.9mm Hg, 160.1mm Hg.

The correct answer is C.
You have to include the CI=90% which is a zscore = 1.645
Take the SD of 13.4 and multiply it by the zscore. Then subtract and add 136. Round up and the answer is C.