In: Math
Use the population of ages {56, 49, 58, 46} of the four U.S. presidents (Lincoln, Garfield, McKinley, Kennedy) when they were assassinated in office. Assume that random samples of size n = 2 are selected with replacement.
1. List the 16 different samples. For example, the samples for age 56 would be
56, 56
56, 49
56, 58
56, 46.
2. After listing all 16 samples, find the mean of each sample, then construct a table representing the sampling distribution of the sample mean. In the table, combine values of the sample mean that are the same.
3. Compare the mean of the population {56, 49, 58, 46} to the mean of the sampling distribution of the sample mean.
4. Do the sample means target the value of the population mean? In general, do sample means make good estimators of population means? Why or why not?
1. The list of 16 differnt sample is
Sample | |
56 | 56 |
56 | 49 |
56 | 58 |
56 | 46 |
49 | 56 |
49 | 49 |
49 | 58 |
49 | 46 |
58 | 56 |
58 | 49 |
58 | 58 |
58 | 46 |
46 | 56 |
46 | 49 |
46 | 58 |
46 | 46 |
2. The mean of each sample, and the sampling distribution of the sample mean is
Sr.No | Sample | Sample mean | Probability | |
1 | 56 | 56 | 56 | 1/16 |
2 | 56 | 49 | 52.5 | 1/16 |
3 | 56 | 58 | 57 | 1/16 |
4 | 56 | 46 | 51 | 1/16 |
5 | 49 | 56 | 52.5 | 1/16 |
6 | 49 | 49 | 49 | 1/16 |
7 | 49 | 58 | 53.5 | 1/16 |
8 | 49 | 46 | 47.5 | 1/16 |
9 | 58 | 56 | 57 | 1/16 |
10 | 58 | 49 | 53.5 | 1/16 |
11 | 58 | 58 | 58 | 1/16 |
12 | 58 | 46 | 52 | 1/16 |
13 | 46 | 56 | 51 | 1/16 |
14 | 46 | 49 | 47.5 | 1/16 |
15 | 46 | 58 | 52 | 1/16 |
16 | 46 | 46 | 46 | 1/16 |
the sampling distribution of the sample mean is
Sr.No | Sample | Sample mean | Probability | |
1 | 56 | 56 | 56 | 1/16 |
2 | 56 | 49 | 52.5 | 2/16 |
3 | 56 | 58 | 57 | 2/16 |
4 | 56 | 46 | 51 | 2/16 |
5 | 49 | 49 | 49 | 1/16 |
6 | 49 | 58 | 53.5 | 2/16 |
7 | 49 | 46 | 47.5 | 2/16 |
8 | 58 | 58 | 58 | 1/16 |
9 | 58 | 46 | 52 | 2/16 |
10 | 46 | 46 | 46 | 1/16 |
3) Using above Table mean of sample means i.e. mean of the sampling distribution of the sample mean is 52.25.
The mean of the population {56, 49, 58, 46} is 52.25.
Thus ,mean of the sampling distribution of the sample mean is equal to the population mean.
4) Since Sample means=52.5=Population mean,we conclude that the sample means do target the value of the population mean.
4.) In general, the sample means do make good estimators of population means since they target the ppopulation mean.