Year 1 Statistics

Question 1

What are the 7 types of sampling?

Answer 1

Simple Random, Cluster, Opportunity, Stratified, Quota, Self-Selected, Systematic

Question 2

What is Simple Random Sampling?

Answer 2

Items in the sample are chosen at random, each item has an equal chance of being picked

Question 3

What is Cluster Sampling?

Answer 3

If a population is divided into subgroups, cluster sampling means taking samples from only a few of those subgroups. E.g. a few schools out of all in the UK

Question 4

What is Opportunity Sampling?

Answer 4

Items are chosen as the opportunity arises, e.g. asking people on the street

Question 5

What is Stratified Sampling?

Answer 5

Sampling is adjusted depending on the size of the subgroup each item comes from. E.g. if a population is 30% male then the sample must be 30% male, or the results must be weighted to the same effect.

Question 6

What is Quota Sampling?

Answer 6

A certain number of items are required per subgroup

Question 7

What is Self-Selected Sampling?

Answer 7

Items have chosen to be in the sample, e.g. volunteers in an internet survey

Question 8

What is Systematic Sampling?

Answer 8

A system is devised to select items in a sample, e.g. every 10th person

Question 9

What is the difference between discrete and continuous data?

Answer 9

Continuous has infinite values. Even if there is a range (for example numbers 1-10, including decimals). Discrete has a fixed number of values. E.g. red, green, blue or 1-10, not including decimals

Question 10

How do you calculate Product Moment Correlation Coefficient (Pearson’s Correlation Coefficient)?

Answer 10

• Stats mode - y=a+bx - Enter data - OPTN - Regression Calculator - R value

Question 11

What is association?

Answer 11

When two variables have an undefined relationship

Question 12

What is correlation?

Answer 12

A linear relationship between two variables?=

Question 13

What is regression?

Answer 13

Finding an equation that can predict the relationship between two variables. A regression line is the same as a line of best fit.

Question 14

What is a skew?

Answer 14

Skew = mean - median Positive Skew - Most values are low, but there are a few extremely high values Negative Skew - Most values are high, but there are a few extremely low values

Question 15

What are the 4 measures of central tendency?

Answer 15

Mean, Median, Mode, Midrange

Question 16

What are the 4 measures of dispersion?

Answer 16

IQR, Range, Standard Deviation, Mean Deviation