To get an average score of 80% (out of four exams), a total of 4*80%=320% is needed, so the minimum required for the 4th test is 320-(75+97+60)=88.
To get an average score of 89% (out of four exams), a total of 4*89%=356% is needed, so the maximum required for the 4th test is 356-(75+97+60)=124, which is impossible.
So the next exam grade must range between 88 and 100 to get a grade b in the class.
Hoped I help! Mark brainly it would help<3