Probability Statistics Exam Review

The composition of the 115^th Congress is 54 Republicans, 44 Democrats, and 2 Independents.  A committee on aid to higher education is to be formed with 3 Senators to be chosen at random to head the committee.  Find the probability that the group of 3 consists of all Republicans

• 15.3%
• 16.3%
• 0.004%
• 24804

The composition of the 115^th Congress is 54 Republicans, 44 Democrats, and 2 Independents.  A committee on aid to higher education is to be formed with 3 Senators to be chosen at random to head the committee.  Find the probability that the group of 3 consists of all Democrats

• 0.007%
• 13244
• 8.2%
• 8.7%

The composition of the 115^th Congress is 54 Republicans, 44 Democrats, and 2 Independents.  A committee on aid to higher education is to be formed with 3 Senators to be chosen at random to head the committee.  Find the probability that the group of 3 consists of two democrats and one republican

• 31.6%
• 0.6%
• 51084
• 33.6%

At the school musical, Rent, 20 seniors, 7 Juniors, and 10 Freshman attended. Choose 3 students at random to feature in a review column for the school newspaper. Find the probability that there will be 1 of each class.

• 2.8%
• 18%
• 1400
• 39%

At the school musical, Rent, 20 seniors, 7 Juniors, and 10 Freshman attended. Choose 3 students at random to feature in a review column for the school newspaper. Find the probability that there will be 0 Seniors.

• 5.2%
• 61%
• 0%
• 8.8%

At the school musical, Rent, 20 seniors, 7 Juniors, and 10 Freshman attended. Choose 3 students at random to feature in a review column for the school newspaper. Find the probability that there will be 3 Juniors

• 3.1%
• 42.9%
• 0.45%
• 1.7%

Construct a probability distribution table and find the mean, variance, and standard deviation.

The probabilities that a randomly selected home has garage space for 0, 1, 2, or 3 cars are 0.22, 0.33, 0.37, and 0.08, respectively.

• mean = 1.31
  variance = 2.53
  std dev = 1.6
• mean= 1.31
  variance = 0.81
  std dev=0.9

Construct a probability distribution table and find the mean, variance, and standard deviation.

The probabilities that a student is registered for 2, 3, 4, or 5 classes are 1%, 34%, 62%, and 3% respectively.

• mean = 3.67
  variance = 0.3
  std dev= 0.55
• mean = 3.67
  variance = 13.77
  std dev= 3.7
• mean = 5.2
  variance = 45.4
  std dev = 6.7
• mean = 5.2
  variance = 18.34
  std dev = 4.3

A burglar alarm system has six fail-safe components.  The probability of each failing is 0.05. Find the probability that exactly 3 will fail.

• 0.1%
• 7.7%
• 2%

A burglar alarm system has six fail-safe components.  The probability of each failing is 0.05. Find the probability that fewer than 2 will fail

• 73.5%
• 3.1%
• 96.7%
• 23.2%