AP. Stat Probability and Randomness

The table represents the probability of guessing correct on a 5 question true-false quiz. Find the mean number of questions one gets correct when guessing.

• 2.5
• 3
• 3.5
• 1.5

The mean temperature in Glens Falls for the month of February is 23 degrees with a standard deviation of 4.2 degrees. Approximately what percent of the days in February would be between 24 and 30 degrees?

• 35.8%
• 68.2%
• 0%
• 50%

• Yes, because all of the probabilities are between 0 and 1 inclusive and the sum of all the probabilities is 1.
• No, all probabilities are not be between 0 and 1 inclusive
• No, the sum of all the probabilities is not 1.
• Yes, because the distribution is symmetric

An assignment of probability must obey which of the following?

• The probability of any event must be a number between 0 and 1, inclusive.
• The sum of all the probabilities of all outcomes in the sample space must be exactly 1.
• The probability of an event is the sum of the outcomes in the sample space which make up the event.
• All of these reasons

Students at University X must be in one of the class ranks—freshman, sophomore, junior, or senior. At University X, 35% of the students are freshmen and 30% are sophomores. If a student is selected at random, the probability that her or she is either a junior or a senior is

• 30%
• 35%
• 65%
• 70%

In a particular game, a fair die is tossed. If the number of spots showing is either four or five, you win $1. If the number of spots showing is six, you win $4. And if the number of spots showing is one, two, or three, you win nothing. You are going to play the game twice.
The probability that you win $4 both times is

• 1/6
• 1/3
• 1/36
• 1/12

Tags

CCSS.HSS.CP.B.8

CCSS.HSS.CP.B.9

Suppose that A and B are two independent events with P(A) = .2 and P(B) = .4. 
P(A∩B^C) is

• .08
• .12
• .52
• .60

Tags

CCSS.HSS.CP.A.2

CCSS.HSS.CP.A.3

CCSS.HSS.CP.B.8

A die is loaded so that the number 6 comes up three times as often as any other number.  What, then, is the probability of rolling a 6?

• .125
• .375
• .500
• .250

Suppose we toss a penny and a nickel. Let A be the event that the penny is a head and B be the event that the nickel is a tail. 
The events A and B are

• Disjoint
• complements
• independent
• dependent

P(Sandals|Pants):

• 4/20
• 6/15
• 1/2
• 2/7

Tags

CCSS.7.SP.C.5

CCSS.7.SP.C.6

CCSS.7.SP.C.7

CCSS.7.SP.C.8