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. Recently, AT&T reported their ARPU was $67.81. Suppose the standard deviation for this population is $18.45. What is the probability that the ARPU will be between $62 and $66 from a random sample of 35 customers?

A) 0.3553
B) 0.4470
C) 0.5619
D) 0.2496