1. A survey of parents is being held by the Principal of a secondary school to find out whether to build a new gymnasium.
Comment on the follow methods suggested to select a sample of parents to take part in a survey.
a. The parents of every student at the school is posted a questionnaire to fill in.
b. The parents of all Year 12 students at the school are asked to take part.
c. A sample of 30 first year students are chosen at random.
d. The Principal invites parents to a meeting and the parents who turn up are asked their opinion.
e. The students names are listed alphabetically and every 10th student is selected and their parents are sent a questionnaire.
2. True or false?
|
a
|
A sample taken for a survey where every member of a population has an equal chance of being chosen is said to be a random sample. |
|
b
|
A sample which does not accurately represent the group from which it is taken is called arandom sample. |
|
c
|
A census involves surveying every member of a population. |
|
d
|
If a sample is taken and it is not random, any conclusions are likely to be biased. |
|
e
|
A census is held every three years in Australia and New Zealand? |
|
f
|
The first 100 students to arrive at school are asked their opinions of the school! The results of this survey be likely to be biased. |
|
g
|
Bias in a survey can be avoided by selecting random samples. |
|
h
|
A sample for a survey on the study habits of all students in a secondary school is taken by selecting every 10th person on the alphabetical school roll. This is a random sample. |
|
i
|
In a random sample every member of the population has an equal chance of being selected. |
|
j
|
A survey which covers every member of a population is called an election. |
