Ecommerce.com, a large Internet retailer, is studying the lead time (elapsed time between when an order is placed and when it is filled) for a sample of recent orders. The lead times are reported in days.

Lead Time (days) Frequency

0 up to 5........... 6

5 up to 10.......... 7

10 up to 15.......... 12

15 up to 20........... 8

20 up to 25........... 7

Total............. 40

a. How many orders were studied?

b. What is the midpoint of the first class?

c. What are the coordinates of the first class for a frequency polygon?

d. Draw a histogram.

e. Draw a frequency polygon.

f. Interpret the lead times using the two charts.