Question

you know how to find the mean by adding up and dividing. in this article, well think about the mean as the balancing point. lets get started!

part 1: find the mean

find the mean of {5, 7}.

find the mean of {5, 6, 7}.

Explanation:

Step1: Recall mean formula

The mean (average) of a set of numbers $x_1,x_2,\cdots,x_n$ is $\bar{x}=\frac{\sum_{i = 1}^{n}x_i}{n}$, where $\sum_{i=1}^{n}x_i=x_1 + x_2+\cdots+x_n$ and $n$ is the number of elements in the set.

Step2: Calculate mean of $\{5,7\}$

Here $n = 2$, $x_1=5$, $x_2 = 7$. Then $\bar{x}=\frac{5 + 7}{2}=\frac{12}{2}=6$.

Step3: Calculate mean of $\{5,6,7\}$

Here $n=3$, $x_1 = 5$, $x_2=6$, $x_3 = 7$. Then $\bar{x}=\frac{5+6 + 7}{3}=\frac{18}{3}=6$.

Answer:

The mean of $\{5,7\}$ is 6.
The mean of $\{5,6,7\}$ is 6.