Problem  Answer 
Find z so that 8% of the standard normal curve lies to the right of z?  
On a test, the scores follow a normal distribution with mean 79 and standard deviation 9. What is the probability that a randomly selected score is above 85??  
In a class, there are 7 girls and 10 boys. In a randomly selected group of 5 students, what is the probability that 2 are girls??  
Using the same information as in the previous problem, what is the probability that 4 of the selected students are boys??  
Of 125 tax returns, the IRS selects 6 to undergo an audit. If 5 of the 125 contain fraudulent info, what is the probability that the IRS finds 1 tax return with fraudulent info??  
Basketball ticket sales during the 1 hour preceding each game averages 300. What is the probability of 40 sales within a oneminute period within an hour of a game??  
A radio callin show receives an average of 72 calls during a onehour broadcast. Find the probability that there will be fewer than 60 calls during a broadcast.?  
Using the same data, find the probability that more than two calls are received in a fourminute period.?  
Richard helps with a tele fund. There is a 65% chance of each person he calls donating. What is the probability that the third person he calls will make the first donation??  
15% of all fires are caused by arson. A random sample of 5 fire insurance claims are studied. What is the expected value of a probability density function of this info??  
Using the same data, what is the standard deviation of the distribution??  
30% of people plan to voluntarily switch jobs within three years. In a sample of 10 people, what is the probability that 3 are planning to change jobs??  
Using the data from the previous problem, find the probability that at least half of them expect to change jobs voluntarily.?  
Using the same data, find the probability that no more than half of them expect to change jobs voluntarily.?  
Using the same data, find the probability that from three to six, including three and six, expect to change jobs voluntarily.?  
The probability that a person requests nonsmoking at a restaurant is .65. A random sample of 12 people make reservations. What is the probability that none request nonsmoking??  
 Problem  Answer 
Using the same information, what is the probability that all will request nonsmoking??  
Using the same information, what is the probability that at least three will request nonsmoking??  
At Red Lobster, an average of 26 patrons request nonsmoking every 4 hours. What is the probability that 10 people will request nonsmoking in an hour??  
Using the same information, what is the probability that no more than three people request a nonsmoking section during the next hour??  
Using the same information, what is the probability that at least four people will request nonsmoking within an hour??  
A spokesperson stated that 25% of all firstgrade pupils entering school were poor. What would be the expected number of poor firstgrade students in a random sample of 3000??  
In a lottery game, a person has 5 winning numbers from 199. 5 numbers are selected randomly. What is the probability that at least 2 of the numbers match a random players'??  
5 fair dice are rolled. What is the probability of rolling 5 1's??  
Using the same information, what is the probability of rolling three of a kind??  
If 2 fair dice are rolled, what is the probability of rolling at least one 1 and/or at least one 5??  
In a game known as Senior Assassins, an average of 8 people are killed each day (assume the kills are independent and random). What is the probability that 2 are killed in a day??  
Using the same information, what is the probability that no one is killed in 6 hours??  
In the game, 3 people on average are killed each week due to a betraying friend. What is the probability of 1 person getting killed due to the betrayal of a friend in one day??  
Using the same information, what is the probability that 2 people die due to a friend's betrayal within half an hour??  
Using the same information, what is the probability that 4 people die due to a friend's betrayal within a week??  
In a high school, there are 300 seniors, of which 25 have betrayed a friend in the game. In a random sample of 4 students, what is the probability that 1 has betrayed a friend??  
