Question

For a sample of nequals64​, find the probability of a sample mean being less than 24.6 if m=25 and sigma=1.15. view page 1 of the standard normal table. For a sample of n=64​, the probability of a sample mean being less than 24.6 if mu = 25 and sigma =1.15 is nothing. ​(Round to four decimal places as​ needed.) Would the given sample mean be considered​ unusual? The sample mean ▼ would not /would be considered unusual because it has a probability that is ▼ less /greater than​ 5%. Enter your answer in the answer box.

Answer 1

Solution :

Given that ,

= 25

= / n = 1.15 / 64 = 0.14375

P( < 24.6) = P(( - ) / < (24.6 - 25) / 0.14375)

= P(z < -2.78 )

Using z table

= 0.0027

   The sample mean would be considered unusual because it has a probability that is less than​ 5%