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Humans possess two sex chromosomes.  A copy of one or the other (equally likely) is contributed to each offspring.  Males have one X chromosome and one Y chromosome.  Females have two X chromosomes.  If a couple has 3 children, what is the probability that they will have at least one boy?

Find the standard deviation of a binomial probability distribution with a sample size of n = 50 and a probability of success of 0.30.

Assume that the mean length of time required to complete the Columbus Marathon was 4.5 hours and that the standard deviation of the times was 0.50 hours.  Assume that the racing times were approximately normally distributed.  What is the probability that a randomly selected runner completed the race in less than 3.6 hours?

A Randomized Block Design is used to compare fleece weights of three breeds of sheep – Merino, Suffolk, and Dorset (we can think of the three breeds as being the three treatments).  The sheep are divided into two weight classes (i.e., two blocks).  Block one contains sheep weighing less than 150 lb and block two contains sheep weighing more than 150 lb.  The fleece weights (in pounds) are as follows:                    Merino          Suffolk          Dorset Block 1          13                  8                  9 Block 2          14                  9                 11                                                                          The partially completed ANOVA table for this experiment is as follows: Source     df          SS            MS            F      Total                29.33333 Breed              26.33333     13.16667    79.00003 Block                     Error                 0.33333        0.16667              The correct values for the Block SS, MS for Blocks, and calculated F value for Blocks, respectively, are:

The owner of a herd of cows wants to determine the influence of the ages of his cows on the amount of calving difficulty that occurs in his herd.  He constructs the following table:                             Age of Cow (in years)                                           0-2     3-5     6-10     over 10   Total No difficulty     40      35       20          5            100 Difficult birth   35      45       15          5            100 Total                  75      80       35        10           200   Find the probability that a randomly selected cow had difficulty in giving birth to her calf and was over 10 yr old.

Suppose that a scientist has 60 mice that she could  use in an experiment involving a new drug to treat a disease.  The scientist decides to use 6 of the 60 available mice for a small preliminary experiment before conducting a larger study.  The scientist arbitrarily begins at row 15 column 1 of the random number table and goes from left to right across the row.  Which one of the following is the correct random sample of 6 mice? For your convenience, here are rows 15 and 16 of the random number table:       Column       Row 1 2 3 4 5 6 15 07119 97336 71048 08178 77233 13916 16 51085 12765 51821 51259 77452 16308

Frame score in beef cattle is based on height at the hips and is used as a measure of skeletal size.  Frame scores range from 1 to 10 with a higher number indicating a taller animal.  Independent random samples of frame scores were selected from the Angus and Simmental breeds of beef cattle with the following results: Angus Simmental 5 7 6 7 7 8 5 6 7 7 6   In the Analysis of Variance table, the calculated F value used to test if the breed means are equal is:

Weights of 40 dogs in a kennel are an example of what type of variable?

Suppose that a random sample of 256 measurements is selected from a population with a mean of 50 lb and a variance of 16 lb2.  What is the mean and standard deviation of the sampling distribution of the sample mean?

The average litter size in Ohio is approximately 8 pigs per litter.  Owners of a particular breed would like to prove that the mean litter size of their breed is greater than 8 pigs per litter.  Therefore, they want to test:      Ho:  μ = 8 pigs/litter      Ha:  μ > 8 pigs/litter They obtain a random sample of 100 litter size records from sows of this breed and find a sample mean of 8.4 pigs per litter and a sample standard deviation of 1 pig per litter.  They decide to use a significance level of α = 0.01. What is the correct conclusion?