The mean time that a certain model of light bulb will last is 400 hours, with a

Question:

The mean time that a certain model of light bulb will last is 400 hours, with a standard deviation equal to 50 hours.
a. Calculate the standardized value for a light bulb that lasts 500 hours.
b. Assuming that the of hours that light bulbs last is bell-shaped, what percentage of bulbs could be expected to last longer than 500 hours?
Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...