Hi, Could use some help with this problem: If the heights of 300 students are no

Question

Hi, Could use some help with this problem:


If the heights of 300 students are normally distributed with mean 68.0 inches and standard deviation 3.0 inches, how many students have heights

a) Greater than 72 inches

b) Less than or equal to 64 inches

c) Between 65 and 71 inches inclusive

d) Equal to 68 inches

Assume the measurements to be recorded to the nearest inch.

Thanks, will rate lifesaver! Please show and explain all work!

Explanation / Answer

Given X~Normal(mean=68, s=3) ------------------------------------------------------------------------------ a) Greater than 72 inches P(X>72) = P((X-mean)/s > (72-68)/3) =P(Z> 1.33) = 0.0917 (check standard normal table) So n=300* 0.0917 = 27.51 Take n=28 ------------------------------------------------------------------------------ b) Less than or equal to 64 inches P(X

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