Question

The mean daily rainfall for a week was 5.5mm.for the first six days the mean rainfall was 1mm.How much rainfall on the seventh day ​

Answer 1

There was 32.5mm of rainfall on the seventh day.

Explanation:

Mean of a data-set:

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

The mean daily rainfall for a week was 5.5mm.for the first six days the mean rainfall was 1mm.

This means that during the week(7 days), the total amount of rain was of:

`6*1 + x = 6 + x`

How much rainfall on the seventh day ​?

This is x. We have that:

`(6 + x)/(7) = 5.5`

`6 + x = 7*5.5`

`6 + x = 38.5`

`x = 38.5 - 6 = 32.5`

There was 32.5mm of rainfall on the seventh day.