Question

Here are Ryan's scores in nine French tests.

4
6
4
7
8
a
6
7
7
The mean of Ryan's nine scores is 6
Work out the value of a.

Answer 1

a = 5

Explanation:

the mean is calculated as

mean =
`(sum)/(count)`

=
`(4+6+4+7+8+a+6+7+7)/(9)` = 6 ( multiply both sides by 9 to clear fraction )

49 + a = 54 ( subtract 49 from both sides )

a = 5