Question

Do running times of American movies differ somehow from running times of French movies? The author investigated this question by randomly selecting 25 recent movies of each type, resulting in the following running times:Am : 94, 90, 95, 93, 128, 95, 125, 91, 104, 116, 162Am : 94, 90, 95, 93, 128, 95, 125, 91, 104, 116, 162102, 90, 110, 92, 113, 116, 90, 97, 103, 95, 120, 102, 90, 110, 92, 113, 116, 90, 97, 103, 95, 120, 109, 91, 138109, 91, 138Fr: 123, 116, 90, 158, 122, 119, 125, 90, 96, 94, 137Fr: 123, 116, 90, 158, 122, 119, 125, 90, 96, 94, 137102, 105, 106, 95, 125, 122, 103, 96, 111, 81102, 105, 106, 95, 125, 122, 103, 96, 111, 81113, 128, 93, 92113, 128, 93, 92Construct a comparative stem-and-leaf display by listing stems in the middle of your paper and then placing the Am leaves out to the left and the Fr leaves out to the right. Then comment on interesting features of the display.

Answer 1

Solution:

The leaf and the stem for the data provided is as below :

Leaf (American)                        Stem                                Leaf (French)

                                                   8              1  

0 0 0 1 1  2 3 4 5 5 5 7               9              0 0 2 3 4 5 6 6

                         9 4 3 2              10             2 3 5 6

                         6 6 3 0              11              1 3 6 9

                             8 5 0             12             2 2 3 5 5 8

                                   8              13             7

                                                    14

                                                    15             8

                                    2              16

Some of the important features of the leaf and the stem plot are as :

1. Most of the American and the French movies have have a time range of 90 - 99 minutes most likely.

2. American movies are unimodal strongly positively skewed, while French movies are bimodal.

3. The median of the American movies is 102 minutes and that of French movies is 106 minutes.