Regular Probability
The probability a student takes AP Statistics and AP Environmental Science is .05. The probability a student takes AP Statistics is .18. What is the probability a student takes AP Environmental Science given that the student takes AP Statistics?
What is .2778
P(AP Environmental Science l AP Statistics) =
P(AP Environmental Science and AP Statistics) / P(AP Statistics)
The probability a family owns a dog is .40, for all families independently. There are 10 houses on a street. The probability that exactly half of the families own a dog is...
What is .2007
The probability you find a defective bag of popcorn is .02, independently. What is the probability the first defective bag will be the 10th bag?
What is .0167
Freshman GPAs at Totally Real High School have a mean of 2.93 and standard devation of .39. What is the probability a randomly selected student has a GPA of between 2 and 3?
What is .5627
Given a normal distribution with a mean of 70 and a standard deviation of 4.5, what is the probability a value is between 60 and 85?
0.986
(8/13)*(7/12) = .36
The probability someone gets a 5 on the AP Statistics test is .15. Assume that scores are independent, even though this is silly. Mr. Otey teaches 10 students. What is the probability that all 10 of them get a 5?
What is (.15)^10
The probability John wears a green shirt is .05 each day, independently. What is the probability it will take him a month or less (assume 30 days) to wear a green shirt?
What is .7854
The class scores on a test are normally distributed, with an average of 78 and a standard deviation of 12 points. What is the probability that a randomly selected student got 70% or less?
What is .2525
In a certain game of chance, your chances of winning are 0.2. If you play the game five times and outcomes are independent, what is the probability you win all five times?
What is .00032
BTA's baseball team has a 70% chance of winning home games and 40% chance of winning away games. There's a 50% chance their next game is a home game, so what is the chance they win it?
What is .55
The probability Bob orders dessert at a restaurant is .11. Each time he visits, his decision about whether to get dessert is independent. He goes out to eat 7 days in a row. What is the probability he gets dessert at least twice during these 7 days?
1-binomcdf(7,.11,1) = .175
The probability it rains is .21, each day, independently. On average, how many days until it rains?
What is 4.76 days
An average female is 5'4'' (64 inches). The standard deviation for female heights is 2.5 inches. Elena is 5'6". What percentage of women are taller than she?
What is 21.19%
It has been estimated that about 30% of frozen chickens contain enough salmonella bacteria to cause illness if improperly cooked. A consumer purchases 12 frozen chickens. Find the probability that the consumer buys exactly 4 contaminated chickens.
0.231
If I am rolling two fair dice, what is the probability that the sum of the two dice is 6?
What is 5/36 or 0.138
The probability it will rain any given day is .21, independently of other days. What is the probability it will rain more than 5 out of the next 7 days?
What is .00049
The probability Logan gets a hit is .15, for each at bat, independently. What is the probability it takes him at least 5 at bats to get a hit?
What is .5221
The average person has 3.64 car accidents in their lifetime with a standard deviation of 1.11. If Anna is in the bottom 20% of claims, how many accidents has Anna had?
TRICK QUESTION! We do not know that car accidents are normally distributed. However if we DO assume that they are normally distributed,
What is 2.71 accidents?
A quarterback completes 44% of his passes, and each pass is independent. It is the beginning of football season, and he has not played any games yet. What is the probability that it takes him at least five passes to complete his first pass?
0.098
If Caroline rolls a die and it shows 4 she wins $2. If it shows anything else, she loses $.50. What is her expected value?
What is $-.08
The probability you will have a tire blowout on any given day is .015, independently. What is the probability you will have between 1 and 3 blowouts this week (school week)?
What is .0728.
The probability the cafeteria serves fish sticks is .03 each day independently. What is the probability it will take them more than 10 days to serve fish sticks?
What is .7374
Freshman GPAs at Totally Real High School have a mean of 2.93 and standard deviation of .39. What is the probability that a randomly selected group of 3 students has a total GPA of more than 9?
T = X1 + X2 + X3
T~N(8.79, .675)
P(T>9) = 1 - normalcdf(9,10000,8.79,.675) = .378
An agent sells life insurance policies to five equally aged, healthy people. According to recent data, the probability of a person living in these conditions for 30 years or more is 2/3. Calculate the probability that after 30 years at least three of the five people are still living.
1-binomialcdf(5,2/3,2) = 0.790