Collecting data

What is meant by discrete data?

• Numbers that you do not know

• Data collected by someone else

• Numbers in decimal form, for example, the height of a person

• Numbers that cannot be shown as decimals, such as the number of children someone has

A question in a questionnaire asks how often people visit the cinema. The question reads 'How often do you visit the cinema?'. Why is this not a good question for a questionnaire?

• Not everyone can answer

• The question is biased

• No time periods

• Asks for personal information

A question in a questionnaire asks people how much they spend a week on food in a canteen. The response boxes are as follows: £1 to £1.99, £2 to £4.99, £5 to £9. Why are these not good response boxes?

• Not everyone can answer

• Asks for personal information

• No overlapping amounts

What is meant by stratified sampling?

• Selecting people at random, for example, out of a hat

• Selecting every nth person, for example, every 5th person from a list

• A proportional representation of the population

• Stopping people at random and using them as the sample

The frequency table shows how many men and women work in an office. A stratified sample of 90 people is to be taken. How many women should be in the sample?

MEN - 152

WOMAN - 208

TOTAL - 360

• 30

• 45

• 52

• 70

​ _________ data is collected by the people who are going to use the data

The three ways to collect data are through ​ ​published data, experiments and ​ ​ ___________

If there are too many people to ask when collecting data what would you use?

When collecting data what do statisticians want to prevent?

• confusing questions

• questions that are difficult to answer

• bias

• all of the above

What type of sample is being described "everyone has an equal chance of getting selected in the population"

• simple random sample

• Systematic sample

• stratified sampling