Chapter 10, Problem 3PT

To determine

To calculate the score for the fifth subject

Answer to Problem 3PT

Fifth subject score should be 94

Explanation of Solution

Given information:

Kevin’s scores are,

88, 92, 82, 94.

The required test score mean is 90.

Formula used:

Mean is,

  $\overline{x}=\frac{{{\displaystyle \sum x}}_i}{n}$

Calculation:

Let, the test score of fifth be “x5”

Therefore for mean, substituting the values in the formula,

  $90=\frac{88+92+82+94+x5}{5}$

So,

  $90=\frac{356+x5}{5}$

On cross- multiplying,

  $356+x5=90\times 5$

So,

  $356+x5=450$

Shifting left-hand side values to right-hand side,

  $x5=450-356$

On solving,

  $x5=94$

Hence, Kevin should score 94 to get mean score as 90