Maths Content

Question 1

STANDARD DEVIATION

Answer 1

Standard deviation (SD) is a measure of how spread out the values in a dataset are around the mean.

It tells you whether the data points tend to be close to the mean or if they are widely scattered.

Question 2

High/Low Standard Deviation

Answer 2

Low = Most of the data points are close to the mean. The results are more consistent.

High = The standard deviation is more spread out from the mean. There is more variability in the scores.

Question 3

TYPES OF DATA

Answer 3

Primary data - Information observed or collected directly from first-hand experience.

Secondary Data - information collected by someone else or for a purpose other than the current one.

Question 4

Levels of measurement

Answer 4

Nominal Data - Data are in separate categories that do not overlap.

Interval Data - Data where the numbers have equal distances between them.

Ordinal Data - Data that reflects subjective experiences. The order is important but the differences between values aren’t precise.

Question 5

Charts and Graphs

Answer 5

Bar Chart - A graph used to represent the frequency of nominal data. A space is left between each bar to indicate the lack of continuity.

Histogram - X axis shows categories of continuous data like year groups or test scores. There are no gaps between the bars to show their continuous nature.

Line Graphs - Also presents continuous data but has a dot to mark the top of where a bar would be. The dots are connected by a line.

Question 6

Correlation, Positive and Negative

Answer 6

An association between two variables. They are illustrated using a scattergram.

Positive Correlation - As one covariable increases the other increases. An example would be, those that who revise more tend to do better in exams.

Negative Correlation - As one covariable increases the other decreases. An example is that those who experience more stress have poorer well-being.

Question 7

Correlation Coefficient

Answer 7

A number represents the strength of a correlation.

A perfect positive correlation is represented by +1.

A perfect negative correlation is represented by -1.

Question 8

Normal DISTRIBUTION

Answer 8

Normal - The mean, median and mode are all the exact mid-point. The distribution is symmetrical around this midpoint. Items that may be normally distributed are IQ or stress levels.

Skewed - A NEGATIVE SKEWED
DISTRIBUTION leans to the
right.

The mean is less than the
median.

This would occur is on a test
where most people scored high
but some scored very low.

Question 9

Skewed DISTRIBUTION

Answer 9

NEGATIVE SKEWED DISTRIBUTION - leans to the right. The mean is less than the median. This would occur on a test where most people scored high but some scored very low.

Positively Skewed DISTRIBUTION - leans to the left The mean is higher than the median. This would occur if we were to look at income distribution.