Collecting data

Taking a sample

Name: ______________________________Date: ______________Score: ______ / 20

1.
What is a population in statistics?
1. Aevery member of the group being studied
2. Bthe people living in a country only
3. Cthe sample you collect data from
2.
You weigh 448 babies out of all those born. What is the sample size?
3.
Why not always collect data from the whole population?
1. Ait usually takes too long, costs too much, or is impossible
2. Bthe answer would be wrong
3. Csamples are always more accurate
4.
A larger sample is generally more reliable than a smaller one.
True False
5.
If you can collect data from the whole population, that is better than using a sample.
True False
6.
Match each word to its meaning.
Write the letter of the matching item in each box:
?population
?sample
?sample size
?biased sample
Ahow many are in the sample
Bone that does not represent the population
Cevery member of the group
Dthe smaller group you collect data from
7.
You weigh 421 babies out of all those born. What is the sample size?
8.
A school has 490 learners and you survey 57 of them. How many learners are in the population?
9.
A school has 556 learners and you survey 67 of them. What is the sample size?
10.
You weigh 430 babies out of all those born. What is the sample size?
11.
A school has 109 learners and you survey 34 of them. How many learners are in the population?
12.
Which sample is likely to give a more reliable result: 13 babies or 104 babies?
1. A104 babies
2. B13 babies
13.
You weigh 23 babies out of all those born. What is the sample size?
14.
You weigh 477 babies out of all those born. What is the sample size?
15.
A school has 322 learners and you survey 42 of them. What is the sample size?
16.
Which sample is likely to give a more reliable result: 10 babies or 50 babies?
1. A10 babies
2. B50 babies
17.
A school has 676 learners and you survey 90 of them. How many learners are in the population?
18.
A school has 350 learners and you survey 78 of them. How many learners are in the population?
19.
Which sample is likely to give a more reliable result: 14 babies or 112 babies?
1. A14 babies
2. B112 babies
20.
You weigh 78 babies out of all those born. What is the sample size?

Answer key

Collecting data — Taking a sample

1.A. every member of the group being studied
2.448
3.A. it usually takes too long, costs too much, or is impossible
4.True
5.True
6.population → every member of the group; sample → the smaller group you collect data from; sample size → how many are in the sample; biased sample → one that does not represent the population
7.421
8.490
9.67
10.430
11.109
12.A. 104 babies
13.23
14.477
15.42
16.B. 50 babies
17.676
18.350
19.B. 112 babies
20.78