Surely somewhere in your text book is the fact that if a random variable has mean and standard deviation then a sample of size n will be (approximately) normally distributed with mean and standard deviation .
Hi all,
In this type normal distribution questions which include "sample", I don't know how to use this sample to solve the question. What is the difference between normal distribution problems and normal sampling questions? I really do have difficulty in solving these type of questions.
For the 1st problem:
z= x-μ (x sample)
---------------------
σ/ n (square root)
μ= 95.25
σ= 27.32
n= 25
102.50 - 95.25
-----------------------
27.32 / 25 (square root)
7.25
----- = 1.326 ~ 1.33 = 0.4082
5.464
1-0.4082 = 0.5918
Is the answer correct?