Question

The population mean and standard deviation are given below. Find the required probability and determine whether the given sample mean would be considered unusual. For a sample of n 69, find the probability of a sample mean being less than 25.1 if u 25 and o 1.34 囲Click the icon to view page 1 of the standard normal table. 囲Click the icon to view page 2 of the standard normal table. For a sample of n-69, the probability of a sample mean being less than 25 1 ifμ-25 ando-1.34 is (Round to four decimal places as needed.) Would the given sample mean be considered unusual? The sample mean be considered unusual because it has a probability that is I 'I than 5%. Enter your answer in the answer box

Answer 1

Please don't hesitate to give a "thumbs up " for the answer, in case you're satisfied with it.

n = 69

We will normalize the distribution using the formula:

Xbar - Mu / (stdev/sqrt(n))

Where,

mu = 25
stdev = 1.34

P(Xbar < 25) = P(Z < 25-25/ (1.34/sqrt(69)) = P(Z<0) = .50

the sample mean "shouldn't" be considered usual because it has a probability that is "more" than 5%