A manager wants to determine whether or not the number of customers making purchases at her 2 stores are the same. Over 40 days she found store A had an average of 85 customers per day making purchases, with a standard deviation of 5. Store B had an average of 90, and standard deviation of 8. Perform a two tailed test of hypothesis, with a 0.05 alpha level to determine whether or not the number of customers making purchases is the same