populations and samples

Question 1

What is a population?

Answer 1

the whole set of items that are of interest.

Question 2

What a census?

Answer 2

measures every member of the population.

Question 3

What is a sample?

Answer 3

a selection of observations taken from a subset of the population which is used to find out about the population as a whole.

Question 4

Give an advantage of a census.

Answer 4

it should give a completely accurate result

Question 5

Give a disadvantage of a census.

Answer 5

. time consuming
. expensive
. hard to process a large quantity of data

Question 6

Give an advantage of a sample.

Answer 6

. fewer people have to respond
. less data to process than a census
. less time consuming and expensive than a census.

Question 7

Give a disadvantage of a sample.

Answer 7

. the data may not be as accurate
. the sample may not be large enough to give information

Question 8

How does the size of the sample affect the validity of any conclusions drawn?

Answer 8

. the size of the sample depends on the required accuracy of any conclusions drawn.
. the larger the sample, the more accurate it is.

Question 9

What is a sampling unit?

Answer 9

individual units of a population

Question 10

What is a sampling frame?

Answer 10

when the sampling units are individually named or numbered to form a list called a sampling frame.