G 11 -T3 - SBQ 1

A bag has 3 red marbles, 2 blue and 4 yellow. What is the theoretical probability of pulling a red?

• 3/10
• 3/9
• 1/9
• 1/3

Evaluate $_8C_5$  

• 336

• 56

• 8/5

• 40,320

What is the probability of tossing a coin 5 times and having it land tails-side-up 4 of the 5 times?

• 7.8 %

• 80 %

• 1.6 %

• 20 %

If you are randomly selecting a day, the probability of selecting a Saturday is 1/7. If 10 days are randomly selected, what is the standard deviation?

• 1.22

• 1

• 1/7

• 1.11

Which of the following could be examples of binomial probabilities? (select all that apply)

• P(success)=0.99, P(failure) = 0.01

• P(A) = 0.4, P(B) = 0.4

• P(A)= 1/3, P(B) = 1/3, P(C) = 1/3

• P(3)= 1/6, P(not 3) = 5/6

Is this a probability distribution?

• No, the sum of p(x) does not equal 1.

• Yes, all p(x) are between 0 and 1.

• No, all p(x) are not between 0 and 1.

• Yes, the sum p(x) is 1.

Find the mean of a binomial distribution with n=50 and p=0.4

• 50

• 4

• 20

• 10

What are the random variables in the given problem.

• x = 1, 2, 3

• x = 0, 1, 2, 3

• x = 2, 3, 4, 5, 6

• x = 0, 2, 4, 6, 8

Given the probability model in the table below, what is the expected value of the random variable?
  X        50          20        5
P(X)     0.1         0.3      0.6

• 14
• 4.67
• 5
• 7.5

A couple has 2 children. What is the probability that both are girls?

• 0.25

• 0.5

• 0.75

• 0.8