Stats

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

When rolling a fair die 100 times, what is the probability of rolling a "4" exactly 25 times? Is this an example of binomial or geometric?

• binomial

• geometric

Which one of these variables is a continuous random variable?

• The time it takes a randomly selected student to complete an exam.

• The number of tattoos a randomly selected person has.

• The number of women taller than 68 inches in a random sample of 5 women. 

• The number of correct guesses on a multiple choice test. 

Which one of these variables is a discrete random variable?

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

• The heights of randomly selected students in the class.

• Distance between the students' home and school.

• Number of pairs of shoes a randomly selected person owns.

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.

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? (Hint: It may help to use the complement.)

• 0.088

• 0.697

• 0.214

• 0.303

Given % of shaded are is 0.9115. Find z - score.

• z = -1.35

• z = 0.91

• z = 1.35

• z = 1.36

Given % of shaded are is 0.3643. Find z - score.

• z = 1.00

• z = 1.12

• z = 1.10

• z = -1.10

Given % of shaded are is 0.9767. Find z - score.

• z = -1.99

• z = 1.99

• z = -0.47

• z = -1.90

Given % of shaded are is 0.2358. Find z - score.

• z = -0.23

• z = -0.63

• z = 0.72

• z = -0.72