Unit 2 - Mechanics and Statistics

Question 1

What does collinear mean?

Answer 1

When:

1. Two line are parallel
2. Two lines share a common point

Question 2

What is a population?

Give an example of one.

Answer 2

A population is everything or everybody being included in an investigation or survey, for example the number of people in Northern Ireland.

Question 3

What is a sample?

Give an example of one.

Answer 3

A sample is a smaller subset of the population, for example 1% of the number of people in Northern Ireland.

Question 4

What are the advantages of using a smaller sample?

Answer 4

The larger the sample then the more accurate will be any conclusions drawn from the sample.

Question 5

What are some of the different reasons for sampling?

Answer 5

1. It might be physically impossible to test the whole population, for example the number of people in Northern Ireland is continually changing with births, deaths etc.
2. Testing the population is possible, but would be too costly. For example, an airline company wants to ask its customers how helpful the staff were. They could ask everyone using their service but this would be too costly in terms of time, personnel, analysing the data collected.
3. Testing the population destroys the product. For example, a light bulb manufacturer could test how long each light bulb will last but in doing so there would be no product left to sell.

Question 6

What is a variable?

Answer 6

A variable is a property or a descriptive term that can take or have different values.

Question 7

What is a discrete variable?

Answer 7

A discrete variable is a variable that can only take certain values.

Question 8

What is a continuous variable?

Answer 8

A continuous variable is a variable that can take any value within the range of measurements appropriate to that variable.