Question

a simple random sample of 10 people were asked how many first cousins they have. the results are listed below. 10, 19, 20, 13, 13, 2, 10, 8, 25, 10 what is the mean number of first cousins for this sample? 10 11.5 13 13.5

Explanation:

Step1: Calculate the sum of the data

$$10 + 19+20 + 13+13+2+10+8+25+10$$
$$=(10\times3)+19 + 20+(13\times2)+2+8+25$$
$$=30+19 + 20+26+2+8+25$$
$$=49+20+26+2+8+25$$
$$=69+26+2+8+25$$
$$=95+2+8+25$$
$$=97+8+25$$
$$=105+25$$
$$=130$$

Step2: Calculate the mean

The formula for the mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $n = 10$ (the number of data points) and $\sum_{i=1}^{n}x_{i}=130$
$$\bar{x}=\frac{130}{10}=13$$

Answer:

13