Statistics

There are \(3\) questions in a test. For each question \(1\) point is awarded for a correct answer and none for a wrong answer. If the probability that Janine correctly answers a question in the test is \(2/3\) determine the probability that she gets zero in the test.

In the ECE Board Examinations, the probability that an examinee will pass each subject is \(0.8\). What is the probability that an examinee will pass at least two subjects out of the three board subjects?

In a multiple choice test, each question is to be answered by selecting \(1\) out of \(5\) choices, of which only \(1\) is right. If there are \(10\) questions in a test, what is the probability of getting \(6\) right of pure guesswork?

From a box containing \(6\) red balls, \(8\) white balls and \(10\) blue balls, one ball is drawn at random. Determine the probability that it is red or white.

From a bag containing \(4\) black balls and \(5\) white balls, two balls are drawn one at a time. Find the probability that both balls are white. Assume that the first ball is returned before the second ball is drawn.

A bag contains \(3\) white and \(5\) black balls. If two balls are drawn in succession without replacement, what is the probability that both balls are black?

An urn contains \(4\) black balls and \(6\) white balls. What is the probability of getting \(1\) black and \(1\) white ball in two consecutive draws from the urn?

From a bag containing \(4\) black balls and \(5\) white balls, two balls are drawn one at a time. Find the probability that one ball is white and one ball is black. Assume that the first ball is returned before the second ball is drawn.

A group of \(3\) people enter a theater after the lights had dimmed. They are shown to the correct group of \(3\) seats by the usher. Each person holds a number stub. What is the probability that each is in the correct seat according to the numbers on seat and stub?

From \(20\) tickets marked with the first \(20\) numerals, one is drawn at random. What is the chance that it will be a multiple of \(3\) or of \(7\)?

The probability of a defect in a collection of bolts is 5%. If a man picks 2 bolts, what is the probability that he does not pick 2 defective bolts?

3 randomly chosen senior high school students were administered a drug test. Each student was evaluated as positive (P) or negative (N). Assume the possible combinations are PPP, PPN, PNP, NPP, PNN, NPN, NNP, NNN, each equally likely. What is the probability that at least 1 student gets a negative result?

The probability that A can solve a given problem is 4/5, that B can solve it is 2/3, and that C can solve it is 3/7. If all three try, compute the probability that the problem will be solved.

Find the upper quartile in the set (0, 1, 3, 4).

In a debate on two issues among 32 people, 16 agreed with the first issue, 10 agreed with the second issue, and of these 7 agreed with both. What is the probability of selecting a person at random who did not agree with either issue?

If 15% of the bolts produced by a machine are defective, determine the probability that out of 5 bolts chosen at random, at most 2 bolts will be defective.

A fair coin is tossed three times. Find the probability that there will appear three heads.

A coin is tossed n times. If it is expected that 7 heads will occur, how many times is the coin tossed?

From past experience, it is known that 90 percent of one-year-old children can distinguish their mother’s voice from a similar sounding female. A random sample of 20 one-year-olds is given this voice recognition test. Find the standard deviation of the number of children who recognize their mother’s voice.

The average of six scores is 83. If the highest score is removed, the average of the remaining scores is 81.2. Find the highest score.