Slides in this set
Higher Tier Handling Data revision
Contents : Questionnaires
Mean from frequency table
Estimating the mean
Cumulative frequency curves
Box and whisker plots
Probability tree diagrams…read more
Be careful when deciding what questions to
Questionnaires ask in a survey or questionnaire
What is your age? Don't be personal
Burning fossil fuels is Don't be leading
dangerous for the earth's
future, buy you
agree?when Don't reduce the number
eat non- of people who can answer
polysaturate margarines or the question
not? Yes or no? Don't be complicated
Here is an alternative set of well constructed questions. They
require yes/no or tick-box answers.
How old are you? 0-20, 21-30, 31-40, 41-50, 0ver 50
Do you agree with burning fossil fuels?
Do you like lemonade?
Which margarine do you eat?
Flora, Stork, Other brand, Don't eat margarine
This last question is very good since all of the possible answers
are covered. Always design your questionnaire to get the data you want.…read more
When it is impossible to ask a whole population to take
SamplingThepart in a survey or a questionnaire, you have to sample
a smaller part of the population.
the Therefore the sample has to be representative of
samplethe population and not be biased.
Here every better
member of a population has an equal chance of being chosen:
Names out of a bag, random numbers on a calculator, etc.
Here the population is firstly divided into categories and the number of
people in each category is found out.
The sample is then made up of these categories in the same proportions
as they are in the population using % or a scaling down factor.
The required numbers in each category are then selected randomly.
The whole population = 215 Lets say the sample is 80 so we divide each
Age Male Female amount by Age Male Female
0-29 34 26 0-29 13 10
30-59 46 54 30-59 17 20
60- 19 36 60- 7 13…read more
Here are 4 scatter diagrams and some
Scatter diagrams questions that may be asked about them
A C E G
B D F H
Strong Weak No Strong
As B increases As D increases NoNolink
between As H increases
positive positive correlation negative
so does A so does C variables
between E and F G decreases
correlation correlation correlation
Describe the type Describe what each diagram shows
of correlation in
Give examples of what
variables A H could be
Draw a line to best A = No. of ice creams sold , B = Temperature
show the link
C = No. of cans of coke sold , D = Temperature
two variables E = No. of crisps sold , F = Temperature
G = No. of cups of coffee sold , H = Temperature…read more
Pie charts Draw a pie chart for the following information
Divide 360 by total to
Multiply up all values
to make angles
900 360 ÷ 900 = 0.4 3600
Check they add up to
C5 3600 and draw the Pie
350 BBC 1
ITV 0 Pie Chart to show the favourite
TV channels at Saint Aidan's
BBC 2…read more