A purchasing manager at a university is investigating which brand of LCD projector to purchase to equip "smart" classrooms. Of major concern to her is the lifetime of the light bulbs used in the projectors. One company has published the following information regarding the lifetimes of asampleof44

bulbs used in its LCD projectors:

14

12

10

8

6

4

2

0

Frequency

4

8

14

10

6

2

7007508008509009501000

Bulb lifetime (in hours)

Based on thishistogram, estimate themeanlifetime (in hours) for the sample of bulbs by this company. Carry your intermediate computations to at least four decimal places, androundyour answer to at least one decimal place.