Question

Your school’s fitness club tracks how many minutes students exercise per day.
However, some entries are missing:

Screenshot 2025-11-25 at 12.30.26 PM.png

Before calculating the class average, you need to decide how to handle the missing values (—).

What is the best way to clean these missing values?

Group of answer choices

Replace missing values with 0

Delete the rows with missing values

Replace missing values with 100 to “reward active students”

Replace missing values with the average minutes exercised

Answer 1

Delete the rows with missing values.

Explanation: for computing the class average you should use the observed data (i.e., compute the mean of the non‑missing minutes). Replacing with 0 or 100 would introduce large, artificial bias; replacing with the mean masks variability and can distort other analyses. If many values are missing or the missingness is not random, consider a principled method (e.g., multiple imputation) instead.