A Key Metric in the Cell Phone Industry Is Average

Multiple Choice

A key metric in the cell phone industry is average revenue per user (ARPU) , which represents the average dollar amount that a customer spends per store visit. In 2011, AT&T reported their ARPU as $63.76. Suppose the standard deviation for this population is $22.50. What is the probability that the ARPU will be between $60 and $63 from a random sample of 38 customers?

A) 0.5517
B) 0.4168
C) 0.2661
D) 0.1515