A dairy producer in Ohio wants to determine if the average milk production of her Holstein cows is greater than 18,000 lb of milk per lactation.  Therefore, she obtains a random sample of n = 100 milk production records from her herd and calculates a sample mean of 18,500 lb and a sample standard deviation of 3,500 lb. Calculate the test statistic needed to test the null hypothesis.

Toyota would like to know how many miles per gallon the average person gets when driving the hybrid Toyota Prius.  A random sample of 225 drivers yields a mean of 50 mpg and a standard deviation of 7.5 mpg.  Find the 90% confidence interval for the population mean for the miles per gallon of the Toyota Prius.

The birth weights in pounds of a sample of 7 calves were as follows: Calf Weight 1 68 2 70 3 64 4 90 5 74 6 72 7 87         Find the variance of the birth weights of this sample of 7 calves.

A farm supply store manager wants to predict monthly sales, Y, for her company using advertising expenditures, X.  She has collected 10 months of data on past performance as shown in the following table. Advertising expenditures, in thousands of dollars, X Monthly sales, Y XY X2 Y2 1.2 101 121.2 1.44 10,201 0.8 92 73.6 0.64 8,464 1.0 110 110.0 1.00 12,100 1.3 120 156.0 1.69 14,400 0.7 90 63.0 0.49 8,100 0.8 82 65.6 0.64 6,724 1.0 93 93.0 1.00 8,649 0.6 75 45.0 0.36 5,625 0.9 91 81.9 0.81 8,281 1.1 105 115.5 1.21 11,025 TOTAL 9.4 959 924.8 9.28 93,569 Calculate the slope of the regression line for the regression of Y on X.

A local consumer reporter wants to compare the average costs of grocery items purchased at three different supermarkets – Kroger, Giant Eagle, and Meier.  Prices (in dollars) were recorded for a sample of 60 randomly selected grocery items at each of the three supermarkets.  In order to reduce item-to-item variation, the prices were recorded for each item on the same day at each supermarket. Item                          Kroger    Giant Eagle    Meier     1) Big Thirst Towel      $1.21       $1.49          $1.59 2) Post Golden Crisp    2.78         2.99            3.35 3) Tylenol Tablets         5.98         5.29            5.98           .                              .              .                   .           .                              .              .                   . 59) Colgate Shave       0.94         1.10            1.19 60) Kidney Beans        0.45          0.56            0.38                                                                                   The results of the Analysis of Variance for this experiment are as follows: Source           df       SS            MS          F     Total                       222.21     Supermarket              2.64       1.32       39.23 Item                        215.59       3.65     108.54 Error                           3.97      0.0337                                                                                What is the correct value of the test statistic for determining whether the three supermarkets have the same average prices?

Which one of the following is not an assumption for the randomized block design?

In a pizza takeout restaurant, the following probability distribution was obtained.  The random variable X represents the number of toppings for a large pizza.                                                                                      x             0          1          2          3          4          P(x)          0.30     0.40     0.20     0.06     0.04          Calculate the mean (µ) of this discrete probability distribution.

Consider the following sample of data points for variable X and variable Y.    X          Y      3          4    5          3    6          2    4          1    3          2    7          3    6          3    5          5    4          4    7          3   What is the variance of variable X?

We are interested in determining whether men’s and women’s attitudes concerning the environment are different.  Therefore, we sample 100 men and 100 women and ask:  “Do you think environmental issues are a major concern”?  Of those sampled, 67 women and 53 men responded that they believe environmental issues are a major concern. Construct a 96% confidence interval for the true difference in population proportions of men and women who believe that environmental issues are a major concern.

The following table shows litter sizes for sows in four breeds of pigs. Yorkshire     Landrace     Hampshire     Duroc      8                   9                   8                 7     10                  9                   7                 8     11                10                   8                 9     11                10                   9                 7       9                  8                                                 49                46                 32               31 – treatment totals     9.8               9.2               8.0              7.5 – sample means     The correct degrees of freedom for total, treatments, and error in the Analysis of Variance table for this problem are ____________.