The table shows the mean number of basketball goals made by four random samples of players from the school team during this year’s season.

Sample #
Sample Mean
Number of Goals
1
7
2
4
3
5
4
8

Is a valid prediction for the mean of the population possible using these samples?
No, there are not enough samples.
Yes, the sample means are all less than 10.
Yes, the variation of the sample means is small.
No, the variation of the sample means is too great.

1 answer

To determine if a valid prediction for the mean of the population can be made using these samples, we can consider the variability of the sample means.

The four sample means are:

  • Sample 1: 7
  • Sample 2: 4
  • Sample 3: 5
  • Sample 4: 8

The range of these sample means is from 4 to 8, and there is some variability among the samples.

Let's evaluate each of the provided options:

  1. "No, there are not enough samples." - It is true that four samples may not provide a robust estimate, but this is not the main issue here.
  2. "Yes, the sample means are all less than 10." - This statement is not inherently valid for predicting the population mean; it only states that the sample means are within a certain range.
  3. "Yes, the variation of the sample means is small." - The variation is somewhat small, but it may not be small enough to make a valid prediction confidently.
  4. "No, the variation of the sample means is too great." - Considering the limited number of samples and the range (4 to 8), there is enough variation to question the validity of making a population mean prediction.

Considering the variation and the limited number of samples, the most appropriate choice is:

No, the variation of the sample means is too great.