2. If the manager wants to be 90% confident that the sample mean is within $23 of the true population mean, how many customers should she include in the sample?

Round thez

z

-value to 3 decimal places and round the number of customers UP to the nearest whole number.

(a) The criticalz

z

-value that will need to be used to calculate the number of customers is

(b) The number of customers that should be included in the sample is