Graphs and Distributions

Question 1

State all 4 rules when working with graphs:

Answer 1

1) Always pencil -> pen

2) Title

3) label axes

4) Scale must work

Question 2

What is data representation?

Answer 2

QUAN data made visual

To see patterns+ trends

Graphs+ charts= mean identified + compared

Question 3

What is a scattergram?

Answer 3

Show relationship

2 scores= 1 dot

Scatter of dots= degree of correlation

Question 4

What is a line graph (freq polygon)?

Answer 4

Uses continuous data

Y- axis = freq

X - axis = continuous data

Dots joined by line = x2 shown at a time

Question 5

What is a bar chart?

Answer 5

Data from categories

Y- axis = freq

X - axis = categories

Data independant

NOT TOUCHING

Question 6

What is a histogram?

Answer 6

Unequal width= freq not height

Y- axis= freq/ f density

X- axis= continuous data

E.g. height, weight

CHARTS =TOUCHING

Question 7

What is a pie chart?

Answer 7

Used for categories

Space given = % (freq)

Circle= 360° = each group in that proportion

x/ total × 360° = x°

Question 8

What is a results table?

Answer 8

Summary of data

Shows 3 M’s

Not range or SD

Not on raw data

Summary para= conclude on data

Question 9

What are distributions?

Answer 9

Shown on Bell Curve

Normal= symmetrical

3 M’s fall at same piont

Link to standard deviation (SD)

Larger SD = greater data spread from mean

Question 10

What is a skewed distribution?

Answer 10

Data by mean= not symmetrical

Mean not at centre

Due to extreme results

Question 11

What is a negative skew?

Answer 11

•Long tail to left

• Most distribution of right

• low extreme score

E.g. easy test, most high marks, few on lower end