In Samantha's English class, her current grade is calculated by finding the average of the scores she received on her terms papers. Samantha's last term paper brought her average up to a 91 from an 89, which was her average from the first three. Samantha claims that she scored a 97 on her fourth term paper. Is Samantha's claim true?

Her average in first three test = 89

This means, her total scores in first three test were = 3 x 89 = 267

Her average in four tests = 91

This means, her total scores in four tests are = 364

267 give the sum of first three test scores. and 364 give the sum of scores with fourth test adding in three tests.

So, subtracting 267 from 364 will give us the scores of Fourth test.

Scores of Fourth test = 364 - 267 = 97

Thus, Samantha's Claim is correct