Posted by **Stephanie F** on Tuesday, December 13, 2011 at 3:45pm.

A new extended-life light bulb has an average service life of 750 hours, with a standard deviation of 50 hours. If the service life of these light bulbs approximates a normal distribution, about what percent of the distribution will be between 600 and 900 hours?

a. 95 percent

` b. 68 percent

c. 34 percent

d. 99.7 percent

e. cannot be determined from the information given.

also please explain how you get the answer...

## Answer this Question

## Related Questions

- statistics - A new extended-life light bulb has an average service life of 750 ...
- statisitics - A company installs 5000 light bulbs, each with an average life of ...
- math - 1) A light bulb producing company states that its lights will last an ...
- statitics - a light bulb manufacture gaurentees that the mean life of a certain ...
- stat - A company installs 5000 light bulbs, each with an average life of 500 ...
- statistics, help - Can someone help me which way can I approach this problem. A ...
- Math - A consumer buys n light bulbs, each of which has a lifetime that has a ...
- Math - A consumer buys n light bulbs, each of which has a lifetime that has a ...
- Statistics - An industrial engineer has found that the standard household light ...
- Statistics - An electrical firm which manufactures a certain type of bulb wants ...