Statistics and Probability Answers

A box contains 4 red, 5 green, and 6 white balls. two balls are drawn at random from the box. what is the probability that the balls drawn include only red and/or green??

A stock market analyst examined the prospects of the shares of a large number of corporations. When the performance of these stocks was investigated one year later, it turned out that 25% performed much better than the market average, 25% much worse, and the remaining 50% about the same as the average. Forty percent of the stocks that turned out to do much better than the market were rated “ good buys” by the analyst, as were 20% of those that did about as well as the market and 10% of those that did much worse. What is the probability that a stock rated a “good buy” by the analyst performed much better than the average?

A publisher sends advertising materials for an accounting text to 80% of all professors teaching the appropriate accounting course. Thirty percent of the professors who received this material adopted the book, as did 10% of the professors who did not receive the material. What is the probability that a professor who adopts the book has received the advertising material?

An inspector examines items coming from an assembly line. A review of his record reveals that he accepts only 8% of all defective items. It was also found that 1% of all items from the assembly line are both defective and accepted by the inspector. What is the probability that a randomly chosen item from this assembly line is defective?

In a bag there are 5 red marbles, 2 green, 4 yellow and 3 blue. Once a marble is drawn it is not replaced. What is the probability of choosing a red and then a yellow marble?

Software filters rely heavily on “blacklists” (lists of known “phishing” URLs) to detect fraudulent e-mails. But such filters typically catch only 20 percent of phishing URLs. Jason receives 16 phishing e-mails.

(a) What is the expected number that would be caught by such a filter?

3.assume the random variable x is normally distributed with mean (wierd character)..(u)=90 and standard deviation o=4 find the indicated probability P(78<x<88) (round="" to="" four="" decimal="" places="" as="" needed)

2. assume the random variable x is normally distributed with mean (wierd character)..(u)=50 and standard deviation o=7 find the indicated probability
P(x>43)=
(round to four decimal places as needed)

12 people sit randomly on 20 seats in a row. What is the probability that each one of them has exactly one neighbour?

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I need the pass this last homework section to graduate and im stumped im horrible with math and im breaking down at this point.. i have 8 questions please someone...

1. assume the random variable x is normally distributed with mean (wierd character)..(u)=80 and standard deviation o=5 find the indicated probability
P(x<70) =
(round to four decimal places as needed)