In: Math
Data from the Bureau of Labor Statistics’ Consumer Expenditure Survey (CE) show that annual expenditures for cellular phone services per consumer unit increased from $237 in 2001 to $634 in 2007. Let the standard deviation of annual cellular expenditure be $52 in 2001 and $207 in 2007.
What is the probability that the average annual expenditure of 125 cellular customers in 2001 exceeded $220? (Round “z” value to 2 decimal places, and final answer to 4 decimal places.) |
Probability |
b. |
What is the probability that the average annual expenditure of 125 cellular customers in 2007 exceeded $607? (Round “z” value to 2 decimal places, and final answer to 4 decimal places.) |
Probability |