An animal scientist wants to determine the degree of association between carcass quality grade (variable X) and selling price per pound of carcass (variable Y).  The data for a random sample of 10 Angus steer carcasses are shown in the following table. Quality grade, X Carcass price per pound, Y 5 $1.09 7 1.19 4 0.99 5 1.04 8 1.21 6 1.18 4 0.94 7 1.15 8 1.23 6 1.12 Find the covariance between carcass quality grade and carcass price per pound.

The owner of Get-A-Way Travel has recently surveyed a random sample of 385 customers of the agency.  He would like to determine if the mean age of the agency’s customers is over 31 years.  If so, he plans to alter the destination of their special cruises and tours.  If not, no changes will be made.  He therefore wants to test:    Ho:  μ = 31 years    Ha:  μ > 31 years If he concludes that the mean age is not over 31 years when in fact it is over 31 years, he makes a ________ error.

The average height of a certain ornamental plant is 14 inches and the standard deviation of the heights is 2 inches.  Find the probability that a randomly selected plant will have a height between 12 and 18 inches.

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 experimental design shown here is a _______________.                                                                                  

Consider the probability distribution shown below for the random variable X:                                                                                                     X             10           20           30           40           50           60      P (X)     0.05        0.20        0.30         0.25        0.10         0.10      Find the mean of this discrete probability distribution.

A random sample of sale prices of homes in Columbus, Ohio yielded the following summary information:      Median = $125,000     Lower quartile = $82,000     Upper quartile = $168,000      Lowest price = $46,000     Highest price = $276,000 Construct a box plot for these data.  Based on this box plot, is the highest selling price of $276,000 a suspect or highly suspect outlier?

Suppose x has a binomial probability distribution with n = 200 and p = 0.70.  We want to determine if it is appropriate to use the normal approximation to the binomial.  Which one of the following statements is true?

We want to estimate the proportion (p) of cows conceiving at first service in an AI program on a particular farm.  How many cows would need to be included in the sample if it was desired to estimate p correct to within 0.05 with probability equal to 0.90?  Assume that we have a prior estimate of p which is equal to 0.60.

According to a study conducted at a university, many adults have experienced lingering “fright” effects from a scary movie or TV show they saw as a teenager.  In a survey of 150 college students, 39 said that they still experience “residual anxiety” from a scary movie or TV show. Perform the calculations needed to determine if the sample size of n = 150 is large enough for large-sample confidence interval procedures to be valid.  Is the sample size large enough?

An animal scientist conducts a study to estimate the proportion of cows of the Charolais breed that require assistance during calving.  A random sample of 500 Charolais cows is selected.  Results of the study show that 100 of the 500 cows in the sample required assistance in giving birth.  Perform the calculations needed to determine whether or not it would be appropriate to construct a large-sample confidence interval for the true population proportion (p) of Charolais cows that require assistance during calving.  What do you conclude (i.e., is it appropriate) and why?