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An animal scientist is interested in determining the proportion of ewes that give birth to twins.  Rather than examine the records for all ewes in the United States, he randomly selects 500 ewes and finds that 220 of them gave birth to twins.  The animal scientist knows that the sample size of n = 500 is large enough for large-sample confidence interval procedures to be valid, because:

Suppose that 20% of the Golden Retrievers in the U.S. have a particular genetic defect.  We randomly select 4 Golden Retrievers from the population consisting of all Golden Retrievers in the U.S.  What is the probability that exactly 1 of the 4 dogs in this sample will have the genetic defect?  To find the answer to this question, you will need to use the equation for the binomial distribution.

A two-factor factorial experiment is conducted to compare fleece weights of Merino, Suffolk, and Dorset ewes fed one of two diets.  Two ewes of each breed are randomly assigned to each diet.  The fleece weights (in pounds) are as follows:                Merino            Suffolk            Dorset        Diet 1          14                   9                    8                     15                 10                    8 Diet 2           13                   8                  11                     12                    9                 12                                                                                   The partially completed ANOVA table is as follows: Source             df           SS             MS           F      Total                          66.2500 Diet                             0.0833       0.0833       0.19992 Breed                        46.5000     23.2500     55.79955 Diet x Breed              17.1667     Error                            2.5000      0.41667                                                                                       Should we test the hypotheses involving differences in mean levels of the main effects of diet and breed?  Assume that we use a significance level of 0.05.

We have three independent events (A, B, and C) where    P(A) = 0.20     P(B) = 0.30     P(C) = 0.40 Find the probability of all three events occurring at the same time.

The following is a valid probability distribution for a discrete random variable, X: X             0           1            2            3        P (X)     0.20       0.30       0.30       0.20    

Suppose that 10% of the Labrador Retrievers in the U.S. have a particular genetic defect.  We randomly select 6 Labs from the population consisting of all Labs in the U.S.  What is the probability that at least 1 (i.e., 1 or more) of the 6 dogs in this sample have the genetic defect?

A population of rabbits has a mean weight of 12 lb with a standard deviation of 3 lb.  A rabbit breeder selects 1,000 samples of 36 rabbits each from this population, calculates the mean weight of the rabbits in each of these 1,000 samples, and then graphs the 1,000 sample means.  The standard deviation of the 1,000 sample means is expected to be equal to:

A two-factor factorial experiment is conducted to compare litter sizes of Yorkshire and Landrace sows derived either from a line unselected for litter size or from a line that has gone through 15 years of selection for increased litter size.  Two sows of each breed are randomly selected from each line.  Their litter sizes are as follows:                                   Yorkshire       Landrace            Unselected line               8                     9                                        9                    10 Selected line                 11                    11                                      10                      9                                                                                     The partially completed ANOVA table is as follows:  Source             df             SS                MS            F  Total                              7.875 Line                               3.125            3.125       3.57 Breed Line x Breed Error                              3.500            0.875                                                                                       Find the mean squares for the line x breed interaction.

A _______________, which is used to compare p treatment (or population) means, is one in which the treatments are randomly assigned to the experimental units, or in which independent random samples are drawn from each of p target populations.

The mean weaning weight in a herd of beef cattle is 520 lb and the standard deviation of the weaning weights is 50 lb.  The probability of a calf weighing less than X lb is 0.20.  What is the value of X?