Blog

The birth weights of a sample of 8 calves (in pounds) are as follows:   66    70    64    88    74    72    87    79 Calculate the variance of this sample of 8 calf birth weights.

We are interested in determining whether men’s and women’s attitudes concerning the environment are different.  Therefore, we sample 100 men and 100 women and ask:  “Do you think environmental issues are a major concern”?  Of those sampled, 67 women and 53 men responded that they believe environmental issues are a major concern. Perform the calculations needed to determine whther or not it would be appropriate to construct a large-sample confidence interval for (p1 – p2).  Is it appropriate?  Why or why not?

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. What are the correct degrees of freedom?

In a pizza takeout restaurant, the following probability distribution was obtained.  The random variable X represents the number of toppings for a large pizza.                                                                                      x             0          1          2          3          4          P(x)          0.30     0.40     0.20     0.06     0.04          Calculate the mean (µ) of this discrete probability distribution.

The weights (in pounds) of 17 pigs are used to construct the following stem-and-leaf display (the first two digits were used as the stem and the last digit was used as the leaf): Stem                   Leaf                                       16          0     5 17          — 18          — 19          — 20          — 21          — 22          2     4     6 23          0     9 24          0     1     2     3     4     5     9 25          3 26          — 27          — 28          0     5   Based on this stem-and-leaf display, the lower quartile is equal to __________ lb.

The weaning weights (in kilograms) of a sample of 6 lambs born and raised on Farmer Jones’ farm are as follows: Lamb Weight 1 30 2 32 3 28 4 42 5 40 6 44 Find the median weaning weight of this sample of 6 lambs.

The heights in inches of young growing trees were measured at a nursery and used to construct the following stem-and-leaf display using the first digit as the stem and the second digit as the leaf: Stem                       Leaves                                     3               2     4 4               0     3     4     5     7     8     9 5               0     1     2     3     4     5 6               1     2     5     6     7 7               0     1 8 9               8 Construct a box plot for these data.  The correct inner and outer fences for the box plot are _______, _______, _______, and _______.

We want to test the hypothesis that the mean number of credit hours taken per semester by OSU undergraduates is less than 16 hours.  Therefore, we obtain a random sample of credit hours for 49 students. The sample mean is 15 hours and the sample standard deviation is 4 hours.  We want to test:    Ho:  μ = 16 hours    Ha:  μ < 16 hours using a significance level (α) = 0.01. Should we reject or not reject the null hypothesis?  Why?

A randomized block design is used to compare postweaning average daily gains of 4 breeds of beef cattle, Hereford, Angus, Charolais, and Simmental (we can think of the breeds at the “treatments”).  The breeds are divided into 3 weight classes (i.e., 3 blocks).  Block 1 contains cattle weighing 450 to 500 lb at the beginning of the experiment, block 2 contains cattle weighing 500 to 550 lb at the beginning of the experiment, and block 3 contains cattle weighing 550 to 600 lb at the beginning of the experiment.  The postweaning average daily gains (in pounds per day) are as follows:  Block Hereford Angus Charolais Simmental 1 3.50 3.60 3.70 3.75 2 3.55 3.63 3.71 3.80 3 3.56 3.62 3.80 3.90 The partially completed ANOVA table for this experiment is as follows: Source df SS MS F Total   .160     Breed   .139 .046 46 Block   .014 .007   Error   .007 .001   Calculate the F statistic for blocks.

The weights in pounds of 23 dogs were used to construct the following stem-and-leaf display using the first digit as the stem and the second digit as the leaf:. Stem     Leaves                                                    3            2     4 4            0     3     4     5     7     8     9 5            0     1     2     3     4     5 6            1     2     5     6     7 7            0     1 8 9            8 Use the stem-and-leaf display to find the lower quartile, median, and upper quartile and then use these values to construct a box plot.  The correct values for the lower outer fence, lower inner fence, upper inner fence, and upper outer fence are ______, ______, ______, and ______ lb, respectively.