Help me work the following problems steps by steps explanation

QUESTION 7

1. 20% of workers believe they will need less than $250,000 when they retire. You randomly select 12workers and ask them how much money they think they will need for retirement.Find the probability that the number of workers who say they will need less than $250,000 when they retire is exactly 5. Please use the formula to do the calculation.
2. A.0.0125
3. B.0.0093
4. C.0.0021
5. D.0.0332

QUESTION 8

1. A random sample of 97 home theater systems has a mean price of $423.97 and a standard deviation of $68.26. With 90% confidencelevel find theerror margin for theconfidenceinterval.
2. Write answer in two decimal points.

QUESTION 9

In a random sample of 9 people, the mean driving distance to work was 22.2 miles and the sample standard deviation was7.2 miles. With 80% confidence interval, calculate the margin of error. Answer your question in two decimal points.

QUESTION 10

1. For a normal distribution= 1.5 and = 22. Fin the probability that 18
3. A.0.2514
4. B.0.0956
5. C.0.9082
6. D.0.9044

QUESTION 11

1. 35% percent of Americans ages 16 to 21 years old say that they would break up with their boyfriend/girlfriend for $10,000. You select at random fifteen 16- to 21-year-olds. What is the probability that the first person who says he or she would break up with their boyfriend/girlfriend for $10,000 is the 8th person selected?
2. A.0.00001
3. B.0.0172
4. C.0.9828
5. D.0.0710

QUESTION 12

1. In a survey of 410U.S. females ages 18-64,237say they have gone to the dentist in the past year.With a 95%confidence interval,find the left end point for the point estimate.
2. write answer in two decimal points.