a video store clerk looked up the number of movies checked out each day. what is the median of the numbers?

Explanation:

Step1: List the data values

The number of movies checked - out each day: 80, 70, 90, 90, 90, 100, 100.

Step2: Arrange the data in ascending order

70, 80, 90, 90, 90, 100, 100.

Step3: Find the middle - value

Since there are 7 data points (an odd number), the median is the $\left(\frac{n + 1}{2}\right)$-th value, where $n=7$. $\frac{7+1}{2}=4$. The 4th value in the ordered list is 90.

Answer:

90