Question

Here are the marks of a student in four exams. 65 80 76 69 The student takes a fifth exam. His mean mark for the five exams is 70 Work out his mark in the fifth exam

Answer 1

mark of the fifth exam = 60

Explanation:

Mean = sum of all marks / number of exam

Mean = 70

Number of exam = 5

Let x =

Mean = sum of all marks / number of exam

70 = (65 + 80 + 76 + 69 + x) / 5

Cross product

70 × 5 = (290 + x)

350 = 290 + x

350 - 290 = x

x = 60

mark of the fifth exam = 60