# Question

A long-life flood lamp has a lifetime that is normally distributed with a mean of 10,000 hours and a standard deviation of 2,525 hours.

a. What percentage of the flood lamps would last for more than 12,000 hours?

b. What lifetime should the manufacturer advertise for these lamps so that only 2% will burn out before the advertised lifetime?

a. What percentage of the flood lamps would last for more than 12,000 hours?

b. What lifetime should the manufacturer advertise for these lamps so that only 2% will burn out before the advertised lifetime?

## Answer to relevant Questions

A study was made of frequent fliers, and it was found that 53% had an income over $65,000 a year. a. Fifteen frequent fliers were selected at random, and their incomes recorded. What is the probability that at least 10 had ...The time that it takes an emergency car repair service to arrive at a car that has broken down is a normally distributed random variable, with a mean of 42 minutes and a standard deviation of 12 minutes. What is the ...The leading brand of toothpaste has a 5% market share. a. A sample of 15 customers is taken. What is the probability that three or fewer of them use the leading brand of toothpaste? b. A sample of four customers is selected. ...A survey by a research company reported that 40% of retired people eat out at least once a week. You run a restaurant, and you are wondering if you should focus more of your advertising on retired people. However, you are ...Suppose the population data of heights of students at your college (the x-values) is normally distributed, with a mean of 167.5 centimetres and a standard deviation of 12 centimetres. a. Sketch the normal distribution of ...Post your question

0