SOLUTION: For women aged​ 18-24, systolic blood pressures​ (in mm​ Hg) are normally distributed with a mean of 114.8 and a standard deviation of 13.1. If 23 women aged​ 18-24 are ran

Algebra ->  Probability-and-statistics -> SOLUTION: For women aged​ 18-24, systolic blood pressures​ (in mm​ Hg) are normally distributed with a mean of 114.8 and a standard deviation of 13.1. If 23 women aged​ 18-24 are ran      Log On


   

Question 1185624: For women aged​ 18-24, systolic blood pressures​ (in mm​ Hg) are normally distributed with a mean of 114.8 and a standard deviation of 13.1. If 23 women aged​ 18-24 are randomly​ selected, find the probability that their mean systolic blood pressure is between 119 and 122.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z=(x bar-mean)/sigma/ssqrt(n)
so this is (119-114.8)/13.1/sqrt (23)
=4.2*sqrt(23)/13.1
=1.54
and 7.2*sqrt(23)/13.1
=2.64
this has probability of 0.0576
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check with 2ndVARS 2 (normal cdf),119,122,114.8,sqrt(23)/13.1)) ENTER, which gives 0.0579, the difference due to less rounding.