Question:
The effect of exercise on the amount of lactic acid in the blood of sportsmen was examined in a study. Eight males were selected at random from those attending a week-long training camp. Blood lactate levels (micrograms/L) were measured on each volunteer before and after playing three games of racquetball, with results as shown in the following table:
|
Player
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
Before
|
13
|
20
|
17
|
13
|
13
|
11
|
15
|
16
|
|
After
|
28
|
37
|
40
|
35
|
30
|
20
|
33
|
29
|
a) Is this paired or unpaired data?
b) Calculate the summary statistics relevant to this problem
c) Compute a 95% confidence interval for the mean change in blood lactate level.
Show all your working.
d) Based on that confidence interval, is there sufficient evidence to conclude that the blood lactate level rises as a result of training?
e) The investigators want to estimate the mean change in blood lactate level to an accuracy of ± 1.0 micrograms per Litre with 95% confidence, using the same measurement process