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Find the variance of a binomial probability distribution with a sample size of n = 40 and a probability of success of 0.60.

The probability distribution for the number X out of 5 randomly selected dentists who use laughing gas is shown below:                                                                                                                            X               0                1                 2                  3                4                  5         P (X)     0.0102       0.0768        0.2304         0.3456        0.2592         0.0778      Find the mean number of dentists out of 5 who use laughing gas.

The heights in inches of young growing trees were measured at a nursery and used to construct the following stem-and-leaf display using the first digit as the stem and the second digit as the leaf: Stem                       Leaves                                     3               2     4 4               0     3     4     5     7     8     9 5               0     1     2     3     4     5 6               1     2     5     6     7 7               0     1 8 9               8 Based on the stem-and-leaf display, the upper quartile for this set of tree heights is __________ inches.

We want to test the hypothesis that the mean yield of a particular variety of corn is less than 150 bushels per acre.  Therefore, we obtain the yields of a random sample of 20 corn fields in which this variety was planted. The average yield of the sample of fields was 140 bushels per acre with a standard deviation of 10 bushels per acre.  We want to test:    Ho:  μ = 150 bushels/acre    Ha:  μ < 150 bushels/acre using a significance level (α) = 0.10. Should we reject or not reject the null hypothesis?  Why?

The grades of 8 students on an exam were as follows: Student Grade 1 66 2 70 3 64 4 88 5 74 6 72 7 87 8 79     Find the range for the grades of these 8 students.

Tests for the differences in the mean levels of the main effects in a factorial experiment are relevant only when the factors do not interact.

Find the variance of a binomial probability distribution with a sample size of n = 25 and a probability of success of 0.30.

Sandoz, a pharmaceutical firm, reports that kidney transplant patients who receive the drug cyclosporine have an 80% chance of surviving the first year.  Suppose a hospital performs 4 kidney transplants and all 4 patients receive cyclosporine.  Assuming that one patient’s survival is independent of another’s, what is the probability that at least one of the 4 patients will be alive at the end of 1 year?

An Animal Scientist wants to estimate the average weaning weight of the Angus breed of beef cattle.  Therefore, he selects a random sample of 100 Angus calves and weighs them on the day they are weaned from their mothers.  The sample mean for these 100 calves is 500 lb and the sample standard deviation is 40 lb.  What is the point estimate of the mean of the entire population of all Angus calves?

The Kimberly Clark Corporation wants to determine how many tissues a box of Kleenex should contain.  Researchers determine that 60 is the average number of tissues used by a typical person during a cold.  Suppose a random sample of 100 Kleenex users yielded a sample mean of 56 tissues and a sample standard deviation of 10 tissues used during a typical cold.  Kimberly Clark wants to test:    Ho:  μ = 60 tissues    Ha:  μ < 60 tissues using a significance level (α) = 0.05. What is the correct value of the test statistic that should be used to test the null hypothesis?