1) An elevator starts at the basement with 8 people (not including the elevator operator) and discharges them all by the time it reaches the top floor, number 6. In how many ways could the operator have perceived the people leaving the elevator if all people look alike to him? what if 8 people consisted of 5 men and 3 women and
EXHIBIT 4: The student body of a large university consists of 60% female students. A random sample of 8 students is selected. (1) Refer to Exhibit 4. What is the probability that among the students in the sample exactly two are female? a. 0.0896 b. 0.2936 c. 0.0413 d. 0.0007 e. None of the above
Problem: A five-number summary for a box plot includes which of the following? a. Q1, Q2, Q3, Q4, total b. Min, median, max, average, frequency total c. Q1, Q2, Q3, Q4, average d. min, Q1, Q2, Q3, max e. None of the above
Problem: The IQ of adults in a certain large population is normally distributed with mean 100 and standard deviation10. If a person is chosen at random form this group. the probability that the person's IQ is less than 85 or greater than 110 is: a. 0.7745. b. 0.9081. c. 0.2255. d. 0.0919. e. none of the above
If 10 federal income tax returns are selected at random, the probability that fewer than two of them will conatin errors is
Suppose the probability that a federal income tax return conatins an arithemetic error is 0.2. If 10 federal income tax returns are selected at random, the probability that fewer than two of them will conatin errors is:
1. Here are some interesting (and imaginary) facts about cockroaches: The average number of roaches per home in the United States is 57; s = 12. The average number of packages of roach killer purchased per family per year is 4.2; s = 1.1. The correlation between roaches in the home and roach killer bought is .5. (a) The Clean
Using the following information about the accuracy of a market research firm: Probability of a favorable study given a favorable market = 0.7 Probability of an unfavorable study given a favorable market = 0.3 Probability of a favorable study given an unfavorable market = 0.05 Probability of an unfavorable study given an un
The following is a payoff table giving profits for various situations: States of Nature Alternatives A B C Alternative 1 120 140 120 Alternative 2 200 100 50 Alternative 3 100 120 180 Do Nothing 0
Population mean = 18.4%, standard deviation = 20%, sample size= 25. Find the probability that the sample mean is less than 20%.
1) in successive rolls of a pair of fair dice, what is the probability of getting 2 sevens before 6 even numbers? 2) suppose that an ordinary deck of 52 cards (contain 4 aces) is randomly divided into 4 hands of 13 cards each. p is the probability that each hand has an ace. Ei is the event that the ith hand has exactly one ac
1) an urn contains n white and m black balls. the balls are withdrawn one at a time until only those of the same color are left. show that with probability n/(n+m) they are all white. 2) an urn contains 5 white and 10 black balls. a fair die is rolled and that number of balls is randomly chose from the urn. what is the probabil
(24) A study by the National Park Service indicates that 60% of the vacationers going to the Rocky Mountain region visit the Yellowstone Park, 30% visit the Tetons, and 15% visit both. What is the probability that a vacationer to Yellowstone will visit the Tetons? a. 25% b. 50% c. 45% d. 90% e. None of the ab
Let X.Y,Z have a joint pdf f(x,y,z)= 2(x+y+z)/3, 0<x<1, 0<y<1, 0<z<1, 0 elsewhere. Find the conditional distribution of X and Y given Z=z, and compute E(X+y|z).
The IQ of children in a certain population is normally distributed with mean 100 and standard deviation 10. If a child is randomly chosen from this group, the probability that the child's IQ is less than 85 or greater than 110 is? a. .0919 b. .2255 c. .9081 d. .7745
How many poker hands consist of 4 clubs and a card of a different suit? a. 48 * C(13,4) b. 39 * C (52,4) c. 48 * C (52,4) d. 39 * C (13,4)
Question: Five horses are running in a race. I bet that Hot Shot will win first place, and Urawinner will win second. What is the probability that I will win?
A normal distribution has a mean of 50 and a standard deviation of 4. a. Compute the probability of a value between 44.0 and 55.0. b. Compute the probability of a value greater than 55.0. c. Compute the probability of a value between 52.0 and 55.0.
A woman has n keys, of which one will open her door. (a) if she tries the keys at random, discarding those that do not work, what is the probability that she will open the door one her kth try? (b) what if she does not discard previously tried keys?
If 8 castles (rooks) are randomly placed on a chessboard, compute the probability that one of the rooks can capture any of the others (i.e. no row or file contains more than one rook).
If it is assumed that all (52 5) poker hands are equally likely, what is the probability of being dealt (a) one pair (a,a,b,c,d) , (b) two pairs (a,a,b,b,c) (c) three of a kind (a,a,a,b,c)
Question: X and Y have the joint pmf described below: (x,y) (1,1) (1,2) (1,3) (2,1) (2,2) (2,3) p(x,y) 2/15 4/15 3/15 1/15 1/15 4/15 and p(x,y)=0 elsewhere. Compute E(Y|X=1) and E(Y|X=2).
A company requires its secretarial employees to demonstrate his/her ability to type more than 45 words per minute in a typing test. The incompetent employees will be terminated. Lucy's typing rate is uniformly distributed between 30 and 50 words per minute. 1. What is the probability that she can type 45 to 50 words per mi
Let X1 and X2 have the joint pdf h(x1, x2)= 2e^(-X1-X2), 0<X1<X2<infinity, zero elsewhere. Find the joint pdf of Y1=2X1 and Y2=X2-X1. I'm having trouble with transforming the boundaries.
Let X1 and X2 have the joint pmf p(x1,x2) = (x1x2)/36 x1=1,2,3 and x2=1,2,3, zero elsewhere. Find first the joint pmf of Y1=X1X2 and Y2=X2, and then find the marginal pmf of Y1.
The National Collegiate association (NCAA) reported that the mean number of hours spent per week on coaching and recruiting by college football assistant coaches during the season 70. A random sample of 50 assistant coaches showed the sample mean to be 68.6 hours, with a standard deviation of 8.2 hours. a. Using the sample
In a certain city, 50 percent of the people consider themselves conservative (C), 25 percent consider themselves liberal (L), and 25 percent consider themselves to be independent (I). During a particular election, 40 percent of the Conservatives voted, 45 percent of the Liberals voted, and 60 percent of the Independents voted.
Question: Suppose we turn over cards simultaneously from two well shuffled decks of ordinary playing cards. We say we obtain an exact match on a particular turn if the same card appears from each deck: for example, the queen of spades against the queen of spades. Let pm equal the probability of at least one exact match. Show
CASE: Mrs. Jones, a robust 50 year old insurance adjuster living in the northern suburbs of Chicago has been diagnosed by a University cardiologist as having a defective heart valve. Although she is otherwise healthy, Jones's heart problem could prove fatal if left untreated. Firm research data are not yet available to predict
Cast a die a number of independent times until a six appears on the up side of the die. Find the probability density function F(x)= P(X<= x).
20. A random sample of n bike helmets manufactured by a certain company is selected. Let X = the number among the n that are flawed, and let p = P(flawed). Assume that only X is observed, rather than the sequence of S's and F's. a. Derive the maximum likelihood estimator of p. If n = 20 and x = 3, what is the estimate? b. Is t