For Exercises7 - 14, use the information from the following application to answer the questions as complete sentences. The life expectancy of a certain brand of light bulb is normally distributed with a mean of 1,500 hours and a standard deviation of 100 hours. Show your work by typing/writing below your calculator function.

Exercise 7

What percent of light bulbs will last less than 1500 hours?

Exercise 8

What percent of light bulbs will last longer than 1250 hours?

Exercise 9

What is the probability that a light bulb will last between 1400 and 1550 hours?

Exercise 10

Find the percentage of light bulbs that will last less than 1480 hours.

Exercise 11

If 80,000 of these light bulbs are produced, how many can be expected to last more than 1500 hours?

Exercise 12

If 80,000 of these light bulbs are produced, how many can be expected to last between 1400 and 1600 hours?

Exercise 13

Determine the minimum number of hours a light bulb must last to be considered in the top 5% of efficiency.

Exercise 14

Determine the values of the light bulb's lifespan that correspond to the upper and lower quartiles.