Data Handling

Question

The rainfall (in mm) in a city on 7 days of a certain week was recorded as follows:

Days

Rain fall (in mm)

Monday

0.0

Tuesday

12.2

Wednesday

2.1

Thursday

0.0

Friday

20.5

Saturday

5.5

Sunday

1.0

(i) Find the range of the rainfall in the above data.
(ii) Find the mean rainfall for the week.
(iii) On how many days was the rainfall less than the mean rainfall.

Solution

(i) Range = (20.5 − 0.0) mm

= 20.5 mm

(ii) Mean rainfall = $\frac{(0.0 + 12.2 + 2.1 + 0.0 + 20.5 + 5.5 + 1.0)}{7}$

$= \frac{41.3}{7} = 5.9 mm$

(iii) For 5 days (i.e., Monday, Wednesday, Thursday, Saturday, Sunday), the rainfall was less than the average rainfall.