# Question

Electric manufactures a decorative Crystal Clear 60-watt light bulb that it advertises will last 1500 hours. Suppose that the lifetimes of the light bulbs are approximately normally distributed, with a mean of 1550 hours and a standard deviation of 57 hours.

(a) What proportion of the light bulbs will last less than the advertised time?

(b) What proportion of the light bulbs will last more than 1650 hours?

(c) What is the probability that a randomly selected GE Crystal Clear 60-watt light bulb will last between 1625 and 1725 hours?

(d) What is the probability that a randomly selected GE Crystal Clear 60-watt light bulb will last longer than 1400 hours?

(a) What proportion of the light bulbs will last less than the advertised time?

(b) What proportion of the light bulbs will last more than 1650 hours?

(c) What is the probability that a randomly selected GE Crystal Clear 60-watt light bulb will last between 1625 and 1725 hours?

(d) What is the probability that a randomly selected GE Crystal Clear 60-watt light bulb will last longer than 1400 hours?

## Answer to relevant Questions

Steel rods are manufactured with a mean length of 25 centimeters (cm). Because of variability in the manufacturing process, the lengths of the rods are approximately normally distributed, with a standard deviation of 0.07 ...The reading speed of sixth-grade students is approximately normal, with a mean speed of 125 words per minute and a standard deviation of 24 words per minute. (a) What is the reading speed of a sixth-grader whose reading ...A random sample of college students aged 18 to 24 years was obtained, and the number of hours of television watched in a typical week was recorded. (a) Use the following normal probability plot to determine if the data could ...The probability of no more than 20 people who want to see Roe v. Wade overturned A discrete random variable is given. Assume the probability of the random variable will be approximated using the normal distribution. Describe ...n = 60, p = 0.4, x = 20 Compute P(x) using the binomial probability formula. Then determine whether the normal distribution can be used as an approximation for the binomial distribution. If so, approximate P(x) and compare ...Post your question

0