Representations of Data

Question 1

Outlier

Answer 1

Value that is 1.5 times the IQR above the UQ or below the LQ

Question 2

Histograms

to calculate height of each bar (frequency density)

Answer 2

area of bar = k x frequency

Question 3

Histograms pt.2
If k = 1 then:
frequency density =

Answer 3

Frequency / class width

Question 4

Drawing frequency polygons

Answer 4

Remember to join the MIDDLE of the top of each bar in a histogram

Question 5

Feature of a Histogram

Answer 5

Area of the bar is proportional to the frequency

Question 6

When comparing data sets, if the data set contains extreme values then

Answer 6

it is better to use the median and IQR rather than mean and standard deviation

Question 7

Bivariate Data

Answer 7

data which has pairs of values for two variables

Question 8

Independent variable also known as

Answer 8

explanatory variable - is on the x-axis

Question 9

Dependent variable also known as

Answer 9

response variable - is on the y-axis

Question 10

Regression Line definition

Answer 10

Straight line that minimises the sum of the squares of the distances of each data point from the line

Question 11

Regression line of y on x written as

Answer 11

y = a + bx
coefficient b tells you the change in y for each unit change in x (contextualise in exam questions)
Use it to predict the values for the dependent variable that are within the given range of data