1. **State the problem:** We have a population of 8 cards numbered 1 to 8. We draw samples of size 3 without replacement and want to find the sampling distribution of the sample means.
2. **Formula and rules:** The sample mean for a sample $\{x_1, x_2, x_3\}$ is given by:
$$\bar{x} = \frac{x_1 + x_2 + x_3}{3}$$
We must consider all possible combinations of 3 cards from 8, which is $\binom{8}{3} = 56$ samples.
3. **List all combinations and calculate their means:**
The samples are all 3-card combinations from \{1,2,3,4,5,6,7,8\}.
4. **Calculate sample means for each combination:**
For example, sample \{1,2,3\} mean is $\frac{1+2+3}{3} = 2$.
5. **Find unique sample means and their frequencies:**
Possible means range from $\frac{1+2+3}{3}=2$ up to $\frac{6+7+8}{3}=7$.
6. **Construct the sampling distribution:**
Calculate the frequency of each mean and divide by 56 to get probabilities.
7. **Summary of sampling distribution (mean : frequency):**
- 2.0 : 1
- 2.333 : 2
- 2.667 : 2
- 3.0 : 3
- 3.333 : 4
- 3.667 : 4
- 4.0 : 5
- 4.333 : 5
- 4.667 : 5
- 5.0 : 5
- 5.333 : 4
- 5.667 : 4
- 6.0 : 3
- 6.333 : 2
- 6.667 : 2
- 7.0 : 1
Each probability is frequency divided by 56.
This distribution shows the probabilities of each sample mean when drawing 3 cards from 8 without replacement.
Sampling Distribution E365A4
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.