The heights in inches of 14 randomly selected adult males in LA are listed as: 71, 67, 70, 59, 71, 68, 67, 71, 80, 68, 74, 69, 72, 68.

1. Display the data in a stem-and-leaf plot.

2. Find the mean.
3. Find the median.
4. Find the mode.
5. Find the range.
6. Find the variance.
7. Find the standard deviation

Find the mean first = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

Mode = most frequently occurring score

Once arranged in order of value, the median = 50th percentile.

Range = highest score - lowest

I'll let you do the calculations.

To answer these questions, we will go step by step. Let's start with creating a stem-and-leaf plot for the given data set.

1. To create a stem-and-leaf plot, we need to organize the data by separating the tens digit (stem) and the ones digit (leaf). Here is the stem-and-leaf plot for the given data set:

5 | 9
6 | 7 7 8 8 8 9
7 | 0 1 1 1 2 4 8
8 | 0

(Note: The numbers on the left of the "|" symbol represent the stem, while the numbers on the right represent the leaves.)

Now let's move on to the next questions:

2. To find the mean, we need to add up all the values in the data set and divide the sum by the number of data points. For this data set, the sum of the values is 963. Since we have 14 data points, the mean can be calculated as 963/14 ≈ 68.79.

3. To find the median, we need to arrange the values in ascending order and locate the middle value. Since we have an even number of data points (14), we need to find the average of the two middle values. After arranging the data in ascending order, we get: 59, 67, 67, 68, 68, 68, 69, 70, 71, 71, 72, 74, 80. The two middle values are 68 and 69, so the median is (68 + 69)/2 = 68.5.

4. To find the mode, we need to identify the value(s) that appear most frequently in the data set. In this case, the mode is 68 since it occurs three times, which is more than any other value.

5. To find the range, we subtract the smallest value from the largest value in the data set. In this case, the smallest value is 59 and the largest value is 80. Therefore, the range is 80 - 59 = 21.

6. To find the variance, we need to calculate the mean squared deviation of each data point from the mean. First, subtract the mean from each value in the data set, square the result, and then find the mean of the squared deviations. In this case, after subtracting the mean from each value, squaring them, and finding the mean, we get a variance of approximately 13.84.

7. To find the standard deviation, we take the square root of the variance. In this case, the standard deviation is approximately √13.84 ≈ 3.72.

These are the answers to the provided questions.