The chart below shows five different baskets of tennis balls
The chart below shows five different baskets of tennis balls.
Baskets
Number of tennis balls
(Population)
1
30
2
18
3
30
4
33
5
36
(a) List all samples of size 2, and compute the mean of each sample.
(b) Compute the mean of the distribution of the sample mean and the population mean. Compare the two values.
(c) Compare the dispersion in the population with that of the sample mean.
| Baskets | Number of tennis balls (Population) |
| 1 | 30 |
| 2 | 18 |
| 3 | 30 |
| 4 | 33 |
| 5 | 36 |
Solution
Taken two at a time mean will have the following values.
| Baskets | Number of tennis balls | Mean of 2 | freq | |
| (Population) | ||||
| 1 | 30 | 24 | 2 | |
| 2 | 18 | 30 | 1 | |
| 3 | 30 | 31.5 | 2 | |
| 4 | 33 | 33 | 2 | |
| 5 | 36 | 34.5 | 1 | |
| 25.50 | 1 | |||
| 27.00 | 1 | |||
| 10 | ||||
| Average | 29.35714 | |||
| Pop mean | 29.4 | |||
| x bar-mu | -0.04286 |

