Question

problems

1. a sample of n = 9 scores has σx = 108. what is the sample mean?
2. a sample of n = 12 scores has σx = 72. what is the sample mean?
3. find the mean for the following set of scores: 2, 7, 9, 4, 5, 3, 0, 6
4. find the mean for the following set of scores: 8, 2, 5, 7, 12, 9, 11, 3, 6
5. using the following informal histogram, what is the

Explanation:

Step1: Recall mean formula

The formula for the sample mean $\bar{X}=\frac{\sum X}{n}$.

Step2: Solve problem 1

Given $n = 9$ and $\sum X=108$, then $\bar{X}=\frac{108}{9}=12$.

Step3: Solve problem 2

Given $n = 12$ and $\sum X = 72$, then $\bar{X}=\frac{72}{12}=6$.

Step4: Solve problem 3

First find $\sum X=2 + 7+9+4+5+3+0+6=36$, and $n = 8$. So $\bar{X}=\frac{36}{8}=4.5$.

Step5: Solve problem 4

First find $\sum X=8 + 2+5+7+12+9+11+3+6=63$, and $n = 9$. So $\bar{X}=\frac{63}{9}=7$.

Step6: Solve problem 5 (no data for calculation in the question, assuming need - to - be - skipped for now)

Answer:

1. 12
2. 6
3. 4.5
4. 7
5. (No calculation possible with given information)