Question

Basil has five numbered cards.

Two of the numbers are hidden. 4 9 9 ? ? 8

The mode of the five numbers is 8.

The mean of the five numbers is 6

c) Work out the two hidden numbers.

Answer 1

The two hidden numbers are 8 and 1.

Explanation:

Mean of a data-set:

The mean of a data-set is given by the sum of all its values divided by the number of values.

Mode of a data-set:

The mode of a data-set is the value that appears the most.

In this question:

4, 9, x, y, 8

Mode is 8 means that at least one of them must be 8, so i will say x is 8 and we have:

4, 9, 8, y, 8

The mean of the five numbers is 6

This means that:

`(4+9+8+y+8)/(5) = 6`

`29+y = 30`

`y = 30 - 29`

`y = 1`

The two hidden numbers are 8 and 1.