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Assume that we have 60 plots of ground and that we want to s…

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?

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Scientists are interested in determining if the mean alkalin…

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:

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The mean weight of a sample of pigs is 220 lb and the standa…

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?

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The following table shows litter sizes for sows in four bree…

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 ____________.                                                                                    

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Scientists want to estimate the difference in twinning rate…

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.

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A large labor union wishes to estimate the mean number of ho…

A large labor union wishes to estimate the mean number of hours per month that union members are absent from work.  The union samples 475 of its members at random and monitors their working time for 1 month.  At the end of the month, the total number of hours absent from work is recorded for each employee.  The mean and standard deviation of the sample are 9.6 hours and 3.6 hours, respectively.  Find the 95% confidence interval that can be used to estimate the mean (μ) of the entire population of number of hours absent from work per month.

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A box of Mr. Phipps Tater Crisps is supposed to contain 156…

A box of Mr. Phipps Tater Crisps is supposed to contain 156 grams of potato chips.  On the side of the box it says “This package is sold by weight, not by volume.  Packed as full as practicable by modern automatic equipment, it contains full net weight indicated.  If it does not appear full when opened, it is because contents have settled during shipping and handling”.  Periodically, the Nabisco Company receives complaints that their boxes of Tater Crisps are not full (i.e., that they contain less than 156 grams of potato chips).  To test this claim, the Nabisco Company randomly samples 10 boxes and finds the average amount of potato chips held by the 10 boxes is 154 grams and the standard deviation is 30 grams. Calculate the appropriate test statistic needed to test the null hypothesis.

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A study published in The Journal of American Academy of Busi…

A study published in The Journal of American Academy of Business examined whether the perception of service quality at five-star hotels in Jamaica differs by gender.  In order to compare the means of two populations (i.e., male vs. female guests), independent random samples were selected from each population, with the results shown in the table below.  Use these data to construct a 96% confidence interval for the difference in the two population means.   Males Females Sample size 127 114 Sample mean score 39.08 38.79 Sample standard deviation 6.73 6.94

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We want to use a confidence interval to estimate the proport…

We want to use a confidence interval to estimate the proportion of students in the College of Food, Agricultural, and Environmental Sciences that are female.  What sample size would be necessary if we want to estimate the true population proportion of female students correct to within 0.03 with probability 0.95?  In an earlier small-scale pilot study we obtained an estimate of the proportion of female students (p) that was equal to 0.48.

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The objects (people, plants, animals, or things) upon which…

The objects (people, plants, animals, or things) upon which the response variable is measured are called the ____________.

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