
Unit 7: Numeracy skills
Approximating and Estimating
Example 2
The following table shows the number of items sold in one year by the Beans Co. in each of its operating districts. Column Y shows the number of salespeople employed in each
district.
Column X | Column Y |
Column Z |
---|---|---|
District | Number of salespeople |
Number of items sold |
SW | 57 |
53,971 |
NW | 38 |
64,562 |
Mid | 31 |
21,123 |
SE | 27 |
47,051 |
NE | 23 |
42,510 |
Task 1. In which district was the highest number of items sold per salesperson?
Task 2. In which district was the lowest number of items sold per salesperson?
Steps:
i. To make handling of figures more manageable, make approximations of the items
sold figures.
Approximation table
District | Salespersons |
Items sold (in thousands) |
---|---|---|
SW | 57 |
54 |
NW | 38 |
64.5 |
Mid | 31 |
21 |
SE | 27 |
47 |
NE | 23 |
42.5 |
Approximation and comparison can eliminate certain districts from the need to calculate accurately.
Task 1. The highest average sales
- Mid and SE have similar numbers of salespeople, but Mid sold far fewer items. Hence Mid can be eliminated.
- SW sold fewer items than NW, but had far more salespeople. Hence SW can be eliminated.
- The districts ‘ left in ‘ for consideration are SE, NW, NE
- Use a calculator to do the division, using the accurate figures, to find the averages of the 3 districts.
SE 47,051 / 27 = 1742.6
NW 64,562 / 38 = 1699
NE 42,510 / 23 = 1848
Hence the highest average sales figures per salesperson was in the NE district
.
Task 2. The lowest average sales per person per district
- From your approximation table it is evident that Mid sold far fewer items than each of NW,SE,NE, despite having similar numbers of salespeople.
- It is not so clear as to how Mid compares with SW, so two calculations are desirable.
SW 53,971 / 57 = 946.86
Mid 21,123 / 31 = 681
Hence Mid district had the lowest average number of items sold per salesperson
SMILE - Numeracy skills by Tom Frank, Eric Williams and Clare Wright, University of Birmingham Careers Centre adapted by Marion Kelt Glasgow Caledonian University is licensed under a Creative Commons Attribution 3.0 Unported License.