Question

alicia received the following seven scores on her math assignments.
80, 90, 10, 75, 90, 95, 99
find the mean and median. which measure of center best represents the data?
○ the mean
○ the median
○ both the mean and the median
○ neither the mean nor the median

Explanation:

Step1: Calculate the mean

First sum all scores, then divide by the number of scores (7).
$\text{Mean} = \frac{80 + 90 + 10 + 75 + 90 + 95 + 99}{7} = \frac{539}{7} = 77$

Step2: Calculate the median

Sort the scores, then pick the middle value.
Sorted scores: $10, 75, 80, 90, 90, 95, 99$
The 4th value (middle of 7 values) is $90$, so $\text{Median} = 90$

Step3: Choose best center measure

The data has an outlier (10), which pulls the mean down. The median is not affected by outliers, so it better represents the typical score.

Answer:

Mean = 77, Median = 90
the median