Binomial Distribution or Not

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 one of these variables is a binomial random variable?

• Time it takes a randomly selected student to complete a multiple choice exam

• Number of textbooks a randomly selected student bought this term 

• Number of women taller than 68 inches in a random sample of 5 women

• Number of CDs a randomly selected person owns

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.)

• 0.962

• 0.132

• 0.831

• 0.250

A test consists of 10 multiple choice questions with five choices for each question.  As an experiment, you GUESS on each and every answer without even reading the questions. 
What is the probability of getting exactly 6 questions correct on this test?

• 0.6%

• 0.00001%

• 0.0064%

• 0.0002%

A test has 8 multiple choice questions with four choices with one correct answer each. If we just randomly guess on each of the 8 questions, what is the probability that you get at least 3 questions correct?

• 0.886

• 0.332

• 0.678

• 0.208

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

• 50

• 4

• 20

• 10

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

• 12

• 15

• 10

• 20

Find the standard deviation of a binomial distribution with n=50 and p=0.4 (Round to the nearest tenth)

• 4.2

• 3.5

• 12.0

• 6.2

Is the distribution below a probability distribution? Why or why not?

• Yes. All P(x) values are between 0 and 1, and ∑P(x) = 1

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

• No, ∑P(x) ≠ 1.