Find the standard deviation of a binomial probability distribution with a sample size of n = 40 and a probability of success of 0.40.

Which one of the following statements about the sampling distribution of the sample mean is incorrect?

A state energy agency mailed questionnaires on energy conservation to 1,000 homeowners in Columbus.  Suppose an experiment consists of randomly selecting one of the returned questionnaires.  Consider the events:    Event A:  the home is constructed of brick    Event B:  the home is more than 30 years old    Event C:  the home is heated with oil A home that is constructed of brick or is not heated with oil would be represented by which one of the following?

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 appropriate test statistic needed to test the null hypothesis?

Independent random samples of litter sizes were selected from the Yorkshire and Landrace breeds of swine, with the following results: Yorkshire Landrace 8 7 9 8 10 9 8 8 9 7 10   We want to analyze these data using Analysis of Variance with a Completely Randomized Design. Calculate the Total Sums of Squares.

Assume that we have 60 plots of ground and that we want to select a random sample of 6 plots for an experiment.  We use row 8 of a random number table and go from left to right across the row of random numbers: 96301     91977     05463     07972    18876     20922     94595     56869     69014     60045     18425     84903     42508     32307 Which 6 plots do we include in our random sample?

Scientists are interested in determining if the mean alkalinity level of water specimens from the Han River in Seoul, Korea is greater than 50 milligrams per liter (mpl).  They select a random sample of 100 water specimens from the river and find a sample mean of 70 mpl and a sample standard deviation of 15 mpl.  They decide to test the hypothesis that the population mean for alkalinity level of water in the Han River exceeds 50 mpl using a significance level of 0.01.  The critical value used to test this hypothesis is:

The mean weight of a sample of pigs is 220 lb and the standard deviation of the weights is 35 lb.  If the data set does not have a symmetric and mound shaped distribution, and we therefore use Chebyshev’s Rule, we would expect what % of the pigs to weigh between 115 and 325 lb?

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 sums of squares for treatments (i.e., breeds) in the Analysis of Variance table for this problem is equal to ____________.                                                                                    

Scientists want to estimate the difference in twinning rate of two lines of beef cattle that have been selected for increased frequency of twin births.  In last spring’s calving season, 40 of the 100 cows in Line 1 and 30 of the 100 cows in Line 2 gave birth to twins. Construct a 90% confidence interval for the true difference in population proportions of cows giving birth to twins in Lines 1 and 2.  In the interest of time you can assume that the sample sizes are large enough that it is appropriate to use a large-sample confidence interval.