Question

According to Crown ATM Network, the mean ATM withdrawal is $67. Assume that the standarddeviation for withdrawals is $35. It is known that the variable "ATM withdrawal" is not normallydistributed. In this case, what is the minimum sample size necessary to use the normal model tocompute probabilities involving the sample mean?

Answer 1

Solution

For this case we have the following parameters:

$\mu=67,\sigma=35$

But we know that the distribution is not normal and we need to find the minimum sample to use the normal model , then the value of n is:

n= 30

Since we need to use the Central limit theorem