Statistic - Math yr9

Quick Test

What is Categorical Nominal Data?

Data that have names, but cannot be ranked in a logical order; for example, brands of car or types of pet.

What is Categorical Ordinal?

Data that can be ranked in a logical order; for example, star ratings or race results

What is Numerical Discrete?

Data that is counted in amounts; for example, number of pens

What is Numerical Continuous?

Data that is measurred; for example, the time it takes to get to school

Is the population the data that is collected from a group?

No, the population is the entire group.

Is the sample the data that is collected from a group?

Yes, the sample is a subset of the population.

Frequency Table

A table that is used to record and organise data

Dot Plot

A way of recording and organising data that displays each member of a sample as an individual dot and assigns each dot a value along an x-axis.

Stem and Leaf plot

A format that is used to display organised data with each piece of data in a plot that is made up of two components.

Histogram

A graph that has columns have no gaps and each column straddles the x-axis value, extending halfway to the values on either side. The x-axis is continuous.

What is the mid-point of 60 and 70?

65

Can graphs be misleading?

Yes

What is a way that can make a graph misleading.

Distorting images, adjusting scales, omitting values, or shortening or lengthening axes

Back-to-back stem-and-leaf plot

A method for comparing two data distributions by attaching two sets of data back to back.

Whats Mean?

The average for the whole group

What is Median?

The middle number

What is Mode?

The most frequent number

What is Range?

The lowest and highest values difference

What is Modal?

The score with the highest frequency.

Grouped Data

The data presented using a frequency table to show a range instead of a value.

How do you find the Mean?

number of all data values / sum of all data values ​OR ∑ x / n

How do you find the Median?

(n + 1) / 2

What is a Symmetrical Distribution graph?

A distribution that has a clear centre and an even spread on either side; also referred to as a bell-shaped or normal distribution.

What is a Positivity Skewed plot?

A plot that has larger amounts of data as the values of the data decrease.

Which one is the definition for a Negatively Skewed plot?

A plot that has larger amounts of data as the values of the data increase.

Which one is the definition for Biomodal Distribution?

A distribution of data that has two modes or peaks.

Which one is preferred for a Symmetrical graph?

Mean and Median

Which one is preferred for a skewed graph?

Median

Is the median less affected by outliers than the mean and preferred when the distribution is not symmetrical?

Yes

Interquartile range (IQR)

The difference between the upper quartile, QU and the lower quartile, QL, expressed as IQR=QU−QL. It is the range of the middle half of the data.

What are the summary statistics examined can be used to analyse data?

• mean

• median

• mode

• range

• IQR.

Is the IQR the range of the middle 50% of data and less affected by outliers than the range?

Yes

!Are you ready for the test?!

Not really tbh