(a)

Scenario: A sample of 26 offshore oil workers took part in a simulated escape exercise, resulting in the accompanying data on time (sec) to complete the escape. Here is a stem-and-leaf display of escape time data.

Stem Leaf
32 57
33 49
34
35 6699
36 34469
37 03345
38 6
39 2347
40 23
41
42 9

Problem: Determine the value of the fourth spread.

Process: ...

Answer: .

(b)

Problem: Are there any outliers in the sample? Any extreme outliers?

Process: ...

Answer: There are no outliers or extreme outliers.

(c)

Problem: Construct a boxplot. Comment on its features.

Process: ...

Answer: The distribution is roughly symmetric with no outliers.

(d)

Problem: By how much could the largest observation, currently 429, be decreased without affecting the value of the fourth spread?

Process: You can decrease the largest observation of a data set to the value of the third quartile () without affecting the value of the fourth spread (IQR).

Answer: .