Unit IV
In a particular game, a marble is randomly chosen from a box that contains three red marbles, one green marble, and six blue marbles. If a red marble is selected, you win $2. If a green marble is selected, you win $4; and if a blue marble is selected, you win nothing. Let X be the amount that you win. the expected value of x is..
$1
Suppose X is a random variable with mean Mx and standard deviation Ox. Suppose Y is a random variable with mean M and standard deviation Oy. The variance of X+Y is...
(ox)^2 + (oy)^2 but only if x and y are independent
The weight of medium-sized tomatoes selected at random from a bin at the local super market is a normal random variable with mean M=10 ounces and a standard deviation of O=1 ounce. Suppose we pick two tomatoes at random from the bin, so the weights of the tomatoes are independent. Referring to the information above, the probability that the difference in the wrights of the two tomatoes exceeds 2 ounces is closest to
0.079
In a certain game of chance, your chances of winning are 0.2. If you play the game 5 times and the outcomes are independent, the probability that you win at most once is
0.7373
A college basketball player makes 80% of his free throws. At the end of a game, his team is losing by two points. He is fouled attempting a three-point shot and is awarded three free throws. Assuming free throw attempts are independent, what is the probability that he makes at least two of his free throws.
0.896
The city council has 6 men and 3 women. If we randomly choose two of them to co-chair a committee, what is the probability that these chair persons are the same gender?
1/2
An event A will occur with probability of 0.5. An event B will occur with probability of 0.6. The probability that both A and B will occur with 0.1. Referring to the information above, the conditional probability of A given B is...
1/6
A business evaluates a proposed venture as follows. It stands to make a profit of $10,000 with probability 3/20, to make a profit of $5000 with a probability of 9/20, to break even with a probability of 1/4, and to loose $5000 with a probability of 3/20. The expected profit on dollars is
3000
According to the national telecommunication and information administration, 50.5% of US households had internet access in 2001. What is the probability that four randomly selected US house holds all had internet access in 2001?
6.5%
Insurance company records indicate that 12% of all teenage drivers have been ticketed for speeding and 9% for going through a red light. If 4% have been ticketed for both, what is the probability that a teen driver has been issued a ticket for speeding but not for running a red light.
8%
Suppose X is a random variable with mean Mx and standard deviation Ox. Suppose Y is a random variable with mean M and standard deviation Oy. The Mean of X + Y is...
Mx + My
The weight of medium-sized tomatoes selected at random from a bin at the local super market is a normal random variable with mean M=10 ounces and a standard deviation of O=1 ounce. Suppose we pick two tomatoes at random from the bin, so the weights of the tomatoes are independent. Referring to the information above, the difference in the weights of the two tomatoes selected (first-second) is a random variable with which of the following distributions.
N(0,1.41)
Which of these has a binomial model?
The number of hits a baseball player gets 6 times at the bat.
Which of these has a geometric model?
The number of people we survey until we find someone who owns an iPod.
An event A will occur with probability of 0.5. An event B will occur with probability of 0.6. The probability that both A and B will occur with 0.1. Referring to the information above, we may conclude...
either A or B always occurs
