Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Statistics > Processing And Representing Data > Flashcards

Processing And Representing Data Flashcards

1
Q

What is a database

A

A collection of information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a two way table

A

A table that shows information in two categories
E.g favourite drinks for boys and girls (not just people in general)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is bivariate data

A

Data with two variables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are pictograms

A

Tables that use images or symbols to represent a set number of items for each picture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What should you do when drawing a pictogram

A

Each picture needs to be the same size

Pictures can be easily divided to show different frequencies

Spacing between pictures is the same in each row

Write a key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do you structure bar charts

A

Height / length of the bar shows the frequency

Bars are equal width with equal spaces between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a vertical line chart

A

A graph that uses vertical lines instead of bars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do you need to do when drawing multiple bar charts.
E.g a dual bar chart

A

A key for what each bar represents

Ensure all bars are the same length

The different bars are all in the same group and touching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a composite bar chart

A

A bar chart showing the total frequency of one category made from specific groups

The total frequency and frequencies in each group CAN be compared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a stem and leaf diagram

A

A diagram which splits numerical data into its stem and leaves
The numbers are written in numerical order

A key shows how to combine the stem and leaves to read the number

E.g 4|3 is 43

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is one benefit of a stem and leaf diagram

A

You can use it to show the shape of the data distribution
But
You can still see the original values

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is back to back stem and leaf diagram

A

Used to compare data

The stem is in the middle and two different data sets are on either side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When do you use a pie chart / what is a pie chart

A

Used to represent frequency
It is a way of displaying data when you want to show how something is shared / divided

The angles at the center of a pie chart add up to 360

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do you calculate the angle you need to use when drawing a pie chart

A

Divide 360° by the total frequency

Using this value multiply each individual frequency to find the angle

T/360 × f

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are comparative pie charts

A

Pie charts used to represent / compare data

The area of each pie chart is in the the same ratio as its frequencies

To compare the frequencies compare the areas

To compare proportions compare individual angles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why are comparative pie charts used

A

Comparing two pie charts of the same size, but with different populations is misleading

17
Q

How do you calculate the radius of your second pie chart

A

R is radius
F is frequency

r¹^2 : r²^2 = f¹ : f²

r²/r¹ = √f² /√f¹

r² = r¹(√f²÷√f¹)

R¹ can be any value you chose

18
Q

What are population pyramids

A

Graphs that show the age groups in a population - usually divide by gender

19
Q

How are population pyramids drawn

A

You have two groups (e.g male and female)
Then you have your age grouping

The center starts at 0 and increases in equal intervals going in opposite directions

Then draw out to the frequencies on each side

20
Q

What is a chloropleth map

A

A map used to classify regions of a geographical area

Regions are shaded with an increasing depth in colour

A key shows what each colour represents

21
Q

Do cholorpleth maps have to be maps

A

No they can be a simple diagram

22
Q

What is a histogram

A

Similar to a bar chart but represents continuous data
Because of this there are no gaps between the lines

23
Q

What is a frequency polygon

A

A graph that joins the top mid points of histograms

24
Q

What is cumulative frequently

A

A running total of all the frequencies in each group

It adds up to the total frequency

25
Q

What is a cumulative step polygon

A

A diagram using cumulative frequency plotted on upper class boundaries

It is not drawn with a smooth curve

Draw a horizontal line to the upper bound then draw a vertical line to its value

26
Q

What is a cumulative frequency diagram

A

A diagram for grouped continuous data

The data points are drawn on the upper boundaries and a smooth curve is used to connect them

They can be used to predict values

27
Q

What Is the shape of distribution

A

The shape formed by the bars in a histogram or by a frequency polygon

28
Q

What are the 3 types of distribution

A

Positive skew - moat data values are on the lower end

Negative skew - most data values are on the higher end

Symmetrical - Distribution is symmetrical / it has no skew

29
Q

How are histograms for unequal class widths drawn

A

By adjusting the height of the bars so area represents frequency

The y axis is replaced by frequency density

30
Q

How do you calculate frequency densitu

A

Frequency / class width

31
Q

Using a histogram how do you estimate the number of people above a certain value

A

Add all the values of (frequency density × class width)

32
Q

When can you compare histograms

A

If they have the same class intervals and the same frequency density scales

33
Q

How can graphs be made to be misleading

A

Scales not starting at 0

Scales that do not increase by the same value each time

Lines on a graph being drawn too thick (hard to read value)

Axes without labels

Graphs and charts without keys

Colours can be used to make some parts stand out

34
Q

How can using 3D diagrams be misleading

A

It can make comparisons difficult

Some parts of the diagram can appear larger than others

It would be hard to see where the value should be read from

35
Q

Why is separating sections of the diagram
(E.g taking out a slice of the pie chart) misleading

A

It makes comparisons difficult

36
Q

What do bar charts and line graphs show

A

Trends and patterns in data - values can be read from a scale if its not too small

37
Q

What do pie charts show

A

Proportions, but not accurate values

38
Q

What do tables show

A

Exact values for different categories but does not show trend patterns as clearly

39
Q

Why do you need to clean data

A

To ensure the data has no missing values
Or to ensure the data is all in the format

Statistics (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions