Probability Dist n Into to Statistics Jeopardy Probability Credits

Probability Answer Which of the following is not a valid probability a.) 2/3 b.) 1/8 c.).70 d.) 5/4

Probability Answer On a multiple choice test with four possible answers for each question, what is the probability of answering a question correctly if you make a random guess? a.) ¼ b.) ¾ c.) ½ d.) 1

Probability Answer A bag contains 4 red marbles, 3 blue marbles, and 5 green marbles. If a marble is randomly selected, what is the probability that it is blue? a.) 1/4 b.) 1/3 c.) 1/5 d.) 1/9

Probability Answer If a person is randomly selected, find the probability that his or her birthday is in May. Ignore leap years. a.) 31/365 b.) 1/31 c.) 1/365 d.) 1/12

Probability Answer An assignment of probability must obey which of the following? a) The probability of any event must be a number between 0 and 1, inclusive. b) The sum of all the probabilities of all outcomes in the sample space must be exactly 1. c) The probability of an event is the sum of the outcomes in the sample space which make up the event. d) All of the above. e) A and B only.

Probability Answer A class consists of 61 students, 10 of which are women. If a student is chosen at random, what is the probability that the student is not a women? a.) 10/61 b.) 1/61 c.) 51/61 d.) 10/51

Probability Answer Which of the following is not a valid probability d.) 5/4 Probabilities are always a value between zero and 1 inclusive. Since 5/4 is greater than 1, it cannot be a valid probability.

Probability Answer On a multiple choice test with four possible answers for each question, what is the probability of answering a question correctly if you make a random guess? a.) ¼ The numerator in our fraction indicates the number of correct choices, the denominator is the total number of choices.

Probability Answer A bag contains 4 red marbles, 3 blue marbles, and 5 green marbles. If a marble is randomly selected, what is the probability that it is blue? a.) 1/4 There are 3 blue marbles out of a total of 12 marbles, so the probability of drawing a blue marble is 4/12 which reduces to 1/4

Probability Answer If a person is randomly selected, find the probability that his or her birthday is in May. Ignore leap years. a.) 31/365 There are 31 days in May out of 365 possible birthdays. (Note: since not all months have the same number of days, we must use days instead of months to find the probability.)

Probability Answer An assignment of probability must obey which of the following? a) The probability of any event must be a number between 0 and 1, inclusive. b) The sum of all the probabilities of all outcomes in the sample space must be exactly 1. c) The probability of an event is the sum of the outcomes in the sample space which make up the event. d) All of the above. a, b, and c are all true statements

Probability Answer A class consists of 61 students, 10 of which are women. If a student is chosen at random, what is the probability that the student is not a women? c.) 51/61 If there are 61 students, 10 of which are women, then there must be 51 (61-10) which are not women. So the probability of not selecting a woman is 51/61

Probability Dist n Answer Determine whether the following is a valid probability distribution X1234 P(x) a.) Yesb.) No

Probability Dist n Answer Determine whether the following is a valid probability distribution X P(x) a.) Yesb.) No

Probability Dist n Answer In a certain town, 60% of adults have a college degree. The accompanying table describes the probability dist n for the number of adults (among 4 randomly selected adults) who have a college degree X01234 P(x) Find the probability that there are at least 2 with college degrees. a.) b.) c.) d.)

Probability Dist n Answer X01234 P(x) Find the probability that there are less than 3 people who have college degrees. a.) b.) c.) d.)

Probability Dist n Answer X01234 P(x) Find the expected number (the mean number) of people with college degrees from 4 randomly chosen people.

Probability Dist n Answer X01234 P(x) Find the standard deviation for the number of people who have college degrees out of 4 randomly selected people

Probability Dist n Ans. Determine whether the following is a valid probability distribution X1234 P(x) b.) No 0 ≤ P(x) ≤ 1—This condition is met ∑ P(x) = 1– The sum of the probabilities =.977 which ≠ 1---so this condition is not met and the dist n is not valid

Probability Dist n Ans. b.) No 0 ≤ P(x) ≤ 1—This condition is not met and the dist n is not valid ∑ P(x) = 1– The sum of the probabilities = 1 X P(x) Determine whether the following is a valid probability distribution

Probability Dist n Ans. X01234 P(x) Find the probability that there are at least 2 with college degrees. b.) The probability of at least 2 having college degrees is found by finding the sum of 2, 3, and 4 having degrees

Probability Dist n Ans. X01234 P(x) Find the probability that there are less than 3 people who have college degrees. c.) The probability of less than 3 people having college degrees is found by finding the sum of 2, 1, and 0 having degrees=

Probability Dist n Ans. X01234 P(x) To find the expected value (the mean) of the distribution μ x = ∑ x P(x) = 0(.0256) + 1(.1536) + 2(.3456) + 3(.3456) + 4(.1296)= 2.4 TI-Tips: X’s in list 1: P(x) in list 2: 1-var stats L 1, L 2

Probability Dist n Ans. X01234 P(x) To find the standard deviation: σ=√∑(x-μ) 2 P(x) (0-2.4) (1-2.4) (2-2.4) (3-2.4) (4-2.4) =.9798

Credits Questions have come from the Test Bank for Basic Practice of Statistics And Essentials of Statistics