Binomial Random Variables

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

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%

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

Which of the following is NOT an assumption of the Binomial distribution?

• All trials must be independent.

• Each trial must be classified as a success or a failure.

• All trials are dependent on each other.

• The number of successes in the trials is counted.

Binomial or Not Binomial?

Rolling a dice ten times and recording how many threes are rolled

• Binomial

• Not Binomial

In a preliminary audition, 40% of the candidates qualified for the finals of a singing competition.
If a sample of 12 candidates is selected at random, find the probability that 8 candidates from the sample qualified for the finals.

Which of the following is false about binomial probabilities?

• Their distributions are approximately symmetric.

• Trials must be fixed.

• Events musts be independent.

• The probability of success must be 0.50

Find the variance of a binomial distribution with 50 trials and p= 0.4

• 12

• 15

• 10

• 20

An algebra 2 test has 6 multiple choice questions with a 25% probability of guessing correctly. If we just randomly guess on each of the 6 questions, how to find the probability that you get exactly 3 questions correct?

• binomcdf(6, 0.25, 3)

• binompdf(6, 0.25, 3)

• binomcdf(6, 0.25, 2)

• 1-binomcdf(6, 0.25, 3)

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

• binomcdf(10, 0.11, 2)

• binomcdf (10, 0.11, 1)

• 1 - binomcdf(10, 0.11, 2)

• 1 - binomcdf(10, 0.11, 1)