A recent survey found that 61 of all adults over 50 wear glasses for driving. In a random sample of ...

A recent survey found that 61 of all adults over 50 wear glasses for driving. In a random
  sample of 70 adults over 50, what is the mean and standard deviation of the number who wear
  glasses? Round to the nearest hundredth when necessary.
 
  A) mean: 42.7; standard deviation: 6.53 B) mean: 27.3 ; standard deviation: 4.08
  C) mean: 27.3 ; standard deviation: 6.53 D) mean: 42.7; standard deviation: 4.08

Q. 2

A radio station claims that the amount of advertising each hour has a mean of 15 minutes and a
  standard deviation of 1.5 minutes. You listen to the radio station for 1 hour and observe that the
  amount of advertising time is 9 minutes.
 
  Calculate the z-score for this amount of advertising
  time.
  A) z = 0.50 B) z = -4.00 C) z = -9 D) z = 4.00

Q. 3

The probability that an individual is left-handed is 0.13 . In a class of 70 students, what is the
  mean and standard deviation of the number of left-handed students? Round to the nearest
  hundredth when necessary.
 
  A) mean: 70; standard deviation: 2.81 B) mean: 9.1; standard deviation: 3.02
  C) mean: 9.1; standard deviation: 2.81 D) mean: 70; standard deviation: 3.02

Q. 4

The amount spent on textbooks for the fall term was recorded for a sample of five hundred
  university students. The mean expenditure was calculated to be 500 and the standard deviation
  of the expenditures was calculated to be 100.
 
  Suppose a randomly selected student reported
  that their textbook expenditure was 700. Calculate the z-score for this student's textbook
  expenditure.
  A) -3 B) +3 C) -2 D) +2

Q. 5

If x is a binomial random variable, calculate  for n = 100 and p = 0.2. Round to three decimal
  places when necessary.
 
  A) 20 B) 16 C) 4.472 D) 4