Type: E

Title: German Cars 1

1)The failure rate in a German class is 30%. In a class of 50 students, find the probability that exactly five students will fail. Use the normal distribution to approximate the binomial distribution. Round the standard deviation to three decimal places to work the problem.

 Type: E

Title: Car Rental 1

2)A local rental car agency has 100 cars. The rental rate for the winter months is 60%. Find the probability that in a given winter month at least 70 cars will be rented. Use the normal distribution to approximate the binomial distribution. Round the standard deviation to three decimal places to work the problem.

 Type: E

Title: Car Rental 2

3)A local rental car agency has 200 cars. The rental rate for the winter months is 60%. Find the probability that in a given winter month at least 140 cars will be rented. Use the normal distribution to approximate the binomial distribution. Round the standard deviation to three decimal places to work the problem.

 Type: E

Title: Car Rental 3

4)A local rental car agency has 50 cars. The rental rate for the winter months is 60%. Find the probability that in a given winter month at least 35 cars will be rented. Use the normal distribution to approximate the binomial distribution. Round the standard deviation to three decimal places to work the problem.

 Type: E

Title: Glasses

5)A recent survey found that 72% of all adults over 50 wear glasses for driving. You randomly select 33 adults over 50, and ask if he or she wears glasses. Decide whether you can use the normal distribution to approximate the binomial distribution. If so, find the mean and standard deviation, If not, explain why.

 Type: E

Title: Police Substation

6)In a recent survey, 83% of the community favored building a police substation in their neighborhood. You randomly select 16 citizens and ask each if he or she thinks the community needs a police substation.
Decide whether you can use the normal distribution to approximate the binomial distribution. If so, find the mean and standard deviation. If not, explain why.

 Type: E

Title: Married

7)According to government data, the probability than an adult was never married is 19%. You randomly select 49 adults and ask if he or she was ever married. Decide whether you can use the normal distribution to approximate the binomial distribution, If so, find the mean and standard deviation, If not, explain why. 

Answers:

1) P(4.5 < X < 5.5) = P(-3.24 < z < -2.93) = 0.0017 - 0.0006 = 0.0011
2) P(x ? 69.5) = 0.0262
3) P(x ? 139.5) = 0.0025
4) P(x ? 34.5) = 0.0968
5) use normal distribution, ? = 23.76 and ? = 2.58.
6) cannot use normal distribution, nq = (16)(0.17) = 2.72 < 5
7) use normal distribution, ? = 9.31 and ? = 2.75.