Financial managers are interested in the speed with which customers who make purchases on credit pay their bills. In addition to calculating the average number of days that unpaid bills (called accounts receivable) remain outstanding, they often prepare an aging schedule. An aging schedule classifies outstanding accounts receivable according to the time that has elapsed since billing and records the proportion of accounts receivable belonging to each classification. A large firm has determined its aging schedule for the past 5 years. These results are shown in the accompanying table. During the past few months, however, the economy has taken a downturn. The company would like to know whether the recession has affected the aging schedule. A random sample of 250 accounts receivable was drawn and each account was classified as follows:

1 = 0−14 days outstanding

2 = 15−29 days outstanding

3 = 30−59 days outstanding

4 = 60 or more days outstanding

Number of Days Proportion of Accounts

Outstanding Receivable Past 5 years

0–14 .............72

15–29 ..............15

30–59 ..............10

60 and more ..........03

Determine whether the aging schedule has changed.