Statistics and Probability Answers

A population of 1,000 students has an average weekly allowance of μ = 350 Php and standard deviation of σ = 56.13 Php. What is the probability that a random sample of size n = 30 will have an average weekly allowance between 335 and 360 Php?

Calculate the mean and the variance of the discrete random variable x which one values 12 and 3, given that P(1)=10/33, P(2)=1/3 and P(3)=12/33

the mean score and the standard score in the statistics test are repectively equal to 80 and 2.5, whereas in the pre calculus test they are respectively equal to 70 and 2. if vince got a score of 85 in statistics and a score of 75 in pre-calculus, in which subject is her standing better assuming normality on both subject?

A box contain 10 black marble, 8 white marble and 6 yellow marble. If a ball is drawn at random, what is the probability of getting black marble and white marble?

A food manufacturing company produces oatmeal cookies that have a sugar content that

is approximately normally distributed. The mean sugar content is 1.1 grams with a standard

deviation of 0.15 gram. Determine the probability that a random sample of 10 oatmeal cookies

will have an average sugar content of greater than 1.2 grams.

Each time Caroline goes shopping she decides whether or not to buy fruit.

The probability that she does buy fruit is 0.4.

Independently, she then decides whether or not to buy a CD, with a probability of 0.3 that she does buy a CD.

Work out the probability that she buys fruit or buys a CD or both.

Box A box B both contain the numbers 1,2,3 and 4 contrast the probability mass function and draw the histogram of the sum when one number from each box is take at a time with replacement

two coins are tossed let T the number of tails that occurs determine the values of the random variable T

A political campaign manager wishes to survey a number of voters to estimate the proportion of those who are in favor of his candidate. If a previous survey shows that 55% of registered voters plans to vote for his candidate, what is the minimum sample size required to make his survey accurate with a 95% confidence level and a margin of error of 2.5%?