Statistics and Probability Answers

a populatpion of 1,000 students has an average weekly allowance of =350 and standard deviation of =56.13 .what is the probability that a random sample of size =30 will have an average weekly allowance between 335 and 360?

There are N urns in which M balls are randomly scattered. Find the probability p that the given (for example, the first) urn contains exactly k balls.

The coin is tossed m times. Find the probability p that the head appears at least k times and at most l times

A student takes a test consisting of 20 true-false questions.

a) what is the probability that the student answers at least seven questions correctly?

b) what is the probability that the student answers at most three questions correctly?

c) what is the probability that the student answers at least four and at most six questions correctly

in the new apartment, 2k new light bulbs are included in the lighting network. Each light bulb burns out within a year with probability p. Find the probability that less than half of the original light bulbs will have to be replaced with new ones within a year.

4 independent shots are fired from the aircraft at the aircraft. The probability of hitting each shot is 0.3. Two hits are obviously enough to destroy (failure) an aircraft; with one hit, the aircraft is hit with a probability of 0.6. Find the probability that the aircraft will be hit.

What is the probability that 40 or more boxes will be delivered on a particular day?

The average monthly salary of 500 teachers of Candelaria East district is

P26,500. If the monthly salaries of the teachers are normally distributed with

standard deviation of P2,500, approximately how many teachers in the district

are earning more than P30,000 monthly?

The average number of calories in a 1.8-ounce chocolate bar is 230. Suppose

that the distribution of calories is approximately normal with a standard

deviation of 10. Find the probability that a randomly selected chocolate bar will

have less than 200 calories.

The division-wide aptitude test in

Mathematics was conducted to students.

The mean of the test is 58 and the standard

deviation is 12. The scores also approximate

the normal distribution. What percent of the

scores is between 55 and 65?

A. 9.87%

B. 18.23%

C. 21.90%

D. 31.77%