Standard and Non Standard Probability

Which formula do you use when two events are mutually exclusive?

• P(A or B) = P(A) + P(B)

• P(A or B) = P(A) + P(B) - P(A∩ B)

• P(A and B) = P(A) * P(B)

• P(A and B) = P(A) - P(B)

Is the situation a mutually exclusive event or non-exclusive (inclusive)

A die is rolled. What is the probability of rolling a 5 or a number greater than 3?

• Exclusive

• Non-Exclusive (Inclusive)

Which of the following shows how to determine P(shaded number or number less than five)?

• 2/8 + 4/8 - 4/8

• 4/8 + 2/8 - 4/8

• 4/8 + 6/8 + 2/8

• 4/8 + 4/8 - 2/8

A bag contains 9 green marbles, 5 yellow marbles and 6 red marbles. You choose one marble. What is the probability of selecting a green or red marble?

• 1/4

• 2/4

• 3/4

• 1

Ian wants to wear colored shirts. He has a 15 shirts in the closet. Five of these are blue, four are red, and the rest are of different colors. What is the probability that he will wear a blue or a red shirt?

• 2/5

• 3/5

• 4/5

• 1

A bag contains 26 balls with letters written on each, one ball for each letter of the alphabet. What is the probability that when you get a ball at random, the letter written on the ball is either a vowel or one of the first five letters of the alphabet?

• 5/26

• 3/13

• 4/13

• 2/26

Find the probability of drawing a Jack or a King from a standard deck of 52 cards.

• 8/13

• 6/13

• 4/13

• 2/13

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have less than 5 accidents?

• 0.6915

• 0.1762

• 0.8238

• -0.93

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

• 68%

• 34%

• 16%

• 2.5%

For a randomly selected subject in a standard normal distribution (mean is 0 and standard deviation is 1), find the probability of a score between 1.37 and 2.42.

• 0.078

• 0.785

• 0.223

• 0.023