Random variables and binomial distributions

An algebra 2 test has 6 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 6 questions, what is the probability that you get exactly 3 questions correct? (You need to figure out the p value first. It is not given to you.)

• 96.2%
• 13.2%
• 8.31%
• 25.0

What does the n stand for in the binomial probability formula?

• Number of trials
• Number of Successes
• Probability of Successes
• Probability of Failures

If you were to flip a coin 20 times, what is the probability you would get exactly 10 heads?

• 50%
• 17.62%
• .58.81%
• 41.19%

What does the p stand for in the binomial probability formula?

• Number of trials
• Number of Successes
• Probability of Successes
• Probability of Failures

When rolling two dice, the probability of rolling doubles is ⅙. Suppose that a game player rolls the dice five times, hoping to roll doubles. Find the probability that the player gets doubles exactly twice in 5 attempts.

• 0.884
• 0.139
• 0.965
• 0.161

The American Red Cross says that about 11% of the U.S. population has Type B blood. A blood drive is being held at your school. What is the probability that at least 2 of the first 10 blood donors has Type B blood? 

• 0.088
• 0.697
• 0.214
• 0.303 

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

• 50

• 4

• 20

• 10

Is this binomial experiment? Shuffle a deck of 52 cards. Turn over the top card. Put the card back in the deck, shuffle again. Repeat the process 50 times. Let X = the number of aces you observe.

• Yes
• No, the trials are not independent.
• No, there are more than 2 outcomes

The table above shows the number of cell phones per household in a small town. Find the mean round to the nearest hundredth.

• 2.80

• 2.93

• 0.10

• 0.14

A discrete random variable X has the probability distributions shown in the table. Find the value of k. (Remember that a valid probability distribution must add up to 1)

• 1/3

• 7/12

• 1/12

• 1/4