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The mean length of time required to complete the Columbus Marathon was 4.5 hours and the standard deviation of the times was 0.50 hours.  Assume that the racing times were approximately normally distributed.  Only 10% of the runners would be expected to complete the race in less than x hours.  Find the value of x.

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

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   Calculate the Total Sum of Squares.

The increasing cost of health care is an important issue today.  Suppose that a random sample of 25 small companies that offer paid health insurance as a benefit was selected.  The sample mean for health insurance cost per worker per month was $300 and the sample standard deviation was $50.  Construct a 90% confidence interval for the population mean (μ).  Assume that any necessary assumptions have been met.

The variables, quantitative or qualitative, that are related to a response variable are called:

A randomized block design is used to compare litter sizes of the Yorkshire and Duroc breeds of sows.  Blocking is used in an attempt to remove the effects of sow age, since it is known that sow age influences litter size.  Each block contains sows of similar ages.  The data collected for this experiment are as follows:                   Yorkshire       Duroc       Block totals Block 1          9 pigs         7 pigs         16 pigs Block 2         10                8                18 Block 3         11                9                 20 Block 4         13              10                 23                                                                             Totals           43              34                 77   The partially completed ANOVA table for this experiment is as follows:   Source          df          SS          MS          F        Total                        23.875 Breed                      10.125      10.125      81.0 Block                       13.375       Error                          0.375                                   Calculate the mean square for blocks and the mean square for error and then calculate the F statistic for blocks.  Do the block means differ (i.e., was blocking effective in removing variation in litter size)?  Use a significance level of α = 0.05.

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?

An insurance company states that their claim office is able to process all death claims for cattle within 5 working days.  Recently there have been several complaints that it took longer than 5 days to process a claim.  Top management sets up a statistical test with a null hypothesis that the average time for processing a claim is 5 days and an alternative hypothesis that the average time for processing a claim is greater than 5 days.  After completing the statistical test, it is concluded that the average exceeds 5 days.  However, it is eventually learned that the mean processing time really is 5 days.  What type of error occurred in the statistical test?

A severe drought has affected several western states in recent years.  A Christmas tree farmer is worried about the drought’s effect on the size of his trees.  To determine whether the growth of his trees has been reduced by the drought, the farmer decides to take a sample of the heights of 6 trees and obtains the following results (recorded in inches): Tree Height 1 60 2 57 3 62 4 69 5 46 6 54 Find the median of the heights of this sample of 6 trees.

One difference between a randomized block experiment and a factorial experiment is that a randomized block experiment only has one observation per cell, whereas a factorial experiment almost always has more than one observation per cell.