Question

Mike earned scores of 88,91,75,and 72 on four math tests determine his score on the fifth test if his average for five tests was 81.
76
79
82
85

Answer 1

Answer:

79.

Explanation:

The average of any number can be obtained by adding all the numbers divided by the total number.

Mike has five maths test and the average given is 81. The scores of four test are  88,91,75,and 72. Let the scores of the fifth test be x.

The average can be calculated as follows:

$\frac{88+91+75+72+x}{5} = 81$

88+91+75+72+x = 405

x = 405- 326

x = 79.

Hence, the score of the fifth test is 79.

Thus, the correct answer is option (2).

Answer 2

Explanation : x = 79 marks

The marks scored by Mike on four math test are 88,91,75 and 72.

Average of marks, A = 81

Let in fifth test he scores x marks.

The formula for finding average is :

$A=\dfrac{sum\ of\ scored\ marks}{no.\ of \ tests}$

$81=\dfrac{88+91+75+72+x}{5}$

$\dfrac{326+x}{5}=81$

$x=79$

In the fifth test he scores 79 marks.

Hence, this is the required solution.