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?

Parking at a large university has become a big problem.  University administrators are interested in determining the average parking time (i.e., the average length of time it takes students to find a place to park on campus) of the students.  An administrator inconspicuously follows 250 students and carefully records their parking times.  Identify the population of interest to the university administration.

A Gallop poll is conducted to estimate the proportion of voters who plan to vote in favor of a certain issue on the ballot.  A random sample of 500 people of voting age is selected.  Results of the poll show that 300 of the 500 people polled plan to vote in favor of the issue.  What is the point estimate of the true population proportion of people who plan to vote in favor of the issue?

A random sample of 4,000 U.S. citizens was asked their opinion concerning gun control.  A total of 2,600 of the 4,000 citizens in the sample stated that they are in favor of gun control legislation.  What is the point estimate of the true population proportion of U.S. citizens who favor gun control legislation?

Assume that a scientist conducts a 2 x 3 factorial experiment.  The Analysis of Variance table is shown below: Source          df          SS               MS               F     Total             17        1.73397 Factor A        1         0.10125       0.10125        23.0375 Factor B        2         0.81195       0.405975       92.3720 A x B             2         0.76803       0.384015       87.3754 Error            12        0.05274        0.004395                                                                                          Based on this analysis and a significance level of α = 0.05, what should the scientist conclude?