Answer: 13
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Explanation:
We're told that there are 50 people in each grade that are surveyed. So that means 50 eighth graders were surveyed.
Add up the values along the bottom row. Set the sum equal to 50 and solve for m
m+8+29 = 50
m+37 = 50
m = 50-37
m = 13
Then note how 13+8+29 = 50 along the bottom row. Also, for the top row we have 17+15+18 = 50 as well.
