What must your average be on the fifth quiz

Question

After taking 4 quizzes, your average is 72 out of 100. What must your average be on the fifth quiz to increase your average to 77?

Answer 1

97

4(72) +x)/5 = 77

288 +x = 385

x = 385-288 = 97

is needed to raise a 72 average to 77 if it's the 5th test of equal weight