Mean + probability - practice problems
Number of problems found: 197
- Three dices
What is the probability that the sum of points 14 will be a roll of three dice (B, M, Z)?
- Pass a test
The student has to pass a test that contains 10 questions. For each of them, he chooses one of 5 answers, with just one being correct. The student did not prepare for the test, so he chooses the answers at random. What are the probabilities that the stude
- Nursing school
The following table shows 1000 nursing school applicants classified according to scores made on a college entrance examination and the quality of the high school from which they graduated, as rated by a group of educators: @TB@ Quality of High Schools S
- Three robots
In a workshop, three robots, Q, R and S, are employed to make chairs Robot Q makes 25% of the chairs Robot R makes 45% of the chairs The remaining chairs are made by Robot S Evidence has shown that 2 percent of the chairs made by robot Q are d
- School student
The probability that a school student has a skateboard is 0.34, the probability that he has a bicycle is 0.81 and the probability that he has a skateboard and a bicycle is 0.22. What is the probability that a randomly selected student has a skateboard or
- Population variance
In a California community college, 60% of students will transfer to a college in the CSU system. The number of students in a sample who will transfer follows a binomial distribution. If 8 students are randomly selected, find the population variance σ² of
- Sample Proportion
In a California community college, 60% of students will transfer to a college in the CSU system. The number of students in a sample who will transfer follows a binomial distribution. 400 students are randomly selected from the college and 224 of them will
- Error rate
The exam has 6 questions. Students have an error rate of 20% and can have a maximum of 1 question wrong. What is the probability that they will succeed?
- Suppose 4
Suppose that 14% of all steel shafts produced by a certain process are nonconforming but can be reworked (rather than having to be scrapped). Consider a random sample of 200 shafts, and let X denote the number among these that are nonconforming and can be
- Rich retirement
Health care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years of age whose net worth is too high to qualify for government health care but who have no private hea
- The vaccination
The vaccination coverage of the population is 80%. Unvaccinated make up 60% of all infected. What percentage are unvaccinated more likely to be infected? Consider N = 10,000 inhabitants and K = 1,000 infected. b. How many times more likely are unvaccinate
- Mortality tables
Mortality tables enable actuaries to obtain the probability that a person at any age will live a specified number of years. Insurance companies and others use such probabilities to determine life-insurance premiums, retirement pensions, and annuity paymen
- An aircraft
An aircraft manufacturing company has submitted bids on two separate airline contracts, A and B. The company feels that it has a 70% chance of winning contract A and a 25% chance of winning contract B. Furthermore, it believes that winning contract A is i
- Binomial probability
What is the binominal probability that at least 4 of the 6 trials (n=6) are succeeded where φ = 0.50?
- Dice 7
A standard number cube is tossed 210 times. What is a reasonable prediction for the number of times the number cube will land on a 5?
- What fraction
What fraction of number 1 to 30 is prime?
- And-or probabilities
P(A ) = 0.53, P(B) = 0.15, and P(A n B ) = 0.18. Find P(A U B ). Round approximations to two decimal places.
- Draw a triangle
We have line segments with lengths of 3cm, 5cm, 6cm, 7cm and 9cm. What is the probability in % that if I randomly select three of them I will be able to draw a triangle?
- The spinner
The spinner below is spun 12 times. It landed on I 4 times, II 7 times, and III 1 time. What is the difference between the experimental and theoretical probabilities of landing on the II?
- Smoker male
For a person selected randomly from a certain population, events A and B are defined as follows. A = event the person is male B = event the person is a smoker. For this particular population, it is found that P(A ) = 0.53, P(B) = 0.15, and P(A n B ) = 0.1
Looking for help with calculating arithmetic mean? Mean - practice problems. Probability - practice problems.