A recent study by the EPA has determined that the amount of contaminants in Minnesota lakes (in parts per million) is normally distributed with mean 64 ppm and variance 17.6, Suppose 35 lakes are randomly selected and sampled. What is the probability that the sample average amount of contaminants is
Calvin Ensor, president of General Telephone Corp, is upset at the number of telephones produced by GTC that have faulty receivers.
Clara Voyant, Whose job is predicting the future for her venture capital company, has just received the statistics describing her company's performance on 1,800 investments last year.
Farmer Braun, Who sells grain to Germany, owns 60 acres of wheat fields. Based on past experience, he knows that the yield from each individual acre is normally distributed with mean 120 bushels and standard deviation 12 bushels.
A ferry carries 25 passengers. The weight of each passenger has a normal distribution with mean 168 pounds and variance 361 pounds squared.
From a population of 125 items with a mean of 105 and a standard deviation of 17,64 items were chosen.
Jonida Martinez, researcher for the Columbian Coffee Corporation, is interested in determining the rate of coffee usage per household in the United States.
From a population of 75 items with a mean of 364 and a variance of 18, 32 items were randomly selected without replacement.
Given a population of size N = 80 with a mean of 22 and a standard deviation of 3.2 what is the probability that a sample of 25 will have a mean between 21 and 23.5?
For a population of size N = 80 with a mean of 8.2 and a standard deviation of 2.1, find the standard error of the mean for the following sample sizes.