JSS 1 Mathematics Third Term Week 1
Topic: STATISTICS 1 – PURPOSE AND DATA COLLECTION
The need for statistics – Statistical data
Suppose a stranger asks you for information about yourself. You could say lot of things. For example: your name, the town you live in; the school you go to; what you ate last night; the things you like; the things you don’t like; etc.
You might also use numbers, for example: I am 12 years old; I have 4 brothers and 2 sisters; I am 171 cm tall and my mass is 48kg; I wear size 6 shoes; my village is 15km from the school; etc.
We use the word data for basic information like this. When we use numbers, the information is called statistical data, or just statistics. The table is showing statistical data about two teams.
| games played | won | lost | |
| Eagles | 18 | 10 | 5 |
| Falcons | 15 | 2 | 8 |
drawn goals for goals against Eagles 36021 Falcons 51937
The statistics in the table give a lot of information about the two teams. Eagles seem to be more successful than Falcons. A good player, looking at the statistics, might prefer to play for Falcons. Thus, statistics can help when taking decisions.
Purposes of Statistics
There are many more serious reasons for gathering statistics than selecting which team to play for. For instance, statistics about population trend can inform the government whether they need to encourage people o have smaller families; statistics about the available of potable water (drinkable water) can inform state and district planners whether or not to budget for pumps and pipelines. The table below shows the leading causes of death by age group in 2002 in a country in East Africa.
age group (years)
| Causes of death | 0-4 | 5-14 | 15-59 | 60+ |
| Malaria/Fever | 40% | 61% | 16% | 26% |
| HIV/AIDS/TB | 4% | 61% | 56% | 17% |
| Heart Disease | n/s | n/s | 6% | 23% |
| Injury/Accident | 32% | 17% | 5% | n/s |
n/s means not significant
Data like this in the table above might tell a Health Minister that more needs to be done about malaria for young people aged 0 to 14 and that HI/AIDS and TB need to be reduced in the 15 – 59 range.
Data collection
It would be impossible to give statistics unless data were collected beforehand. To be able to collect data, you need to be able to count. You also need to be able to write down, or record, the data clearly. The table below shows same data collected in two different ways by two students.
(a) bus, car, car, car, lorry, bicycle, bicycle, car, car, lorry, bicycle, car.
(b)
| Vehicles | Tally | Total |
| Car | IIIIII | 6 |
| Bus | I | 1 |
| Lorry | II | 2 |
| Taxi | ||
| Bicycle | III | 3 |
| Motorbike |
The first student (a) tried to write down every vehicle as it came by. When two bicycles came by she did not have time to write down properly. It is easy to make mistakes when counting this student’s totals.
The second student (b) spent some time before beginning to record. When a vehicle came by he made a tally. iT is easy to count his total. He wrote down all the vehicles he could think of in a column. When a vehicle came by he made a tally. It is easy to count his totals.