Question

a car salesman has 9 used cars for sale. they have a mean price of $3000. what is the total price of all 9 cars?

Explanation:

Step1: Recall mean - total relationship

The formula for the mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $\bar{x}$ is the mean, $n$ is the number of data - points, and $\sum_{i = 1}^{n}x_{i}$ is the total. We can re - arrange it to find the total: $\sum_{i = 1}^{n}x_{i}=n\times\bar{x}$.

Step2: Substitute values

Here, $n = 9$ (the number of cars) and $\bar{x}=3000$ (the mean price). So, $\sum_{i = 1}^{9}x_{i}=9\times3000$.
$9\times3000 = 27000$

Answer:

$27000$