presentation of quantitative data

Question 1

feature of summarising data in a table

Answer 1

-results arent raw scores, the data has been converted into descriptive statistics

Question 2

3 features of a bar chart

Answer 2

-allows differences in data to be clearly seen
-used for discrete data (data divided into categories)
-bars dont touch- shows we’re dealing with separate conditions

Question 3

2 features of histogram

Answer 3

-bars touch- we are dealing with continuous data
-x-axis has equal sized intervals of one category, y-axis represents frequency

Question 4

feature of scattergrams

Answer 4

-show association between covariables

Question 5

what is a normal distribution (2)

Answer 5

symmetrical spread of data- forms a bell-shape
mean, median and mode are all located at the highest peak

Question 6

what is a skewed distribution

Answer 6

data is unsymmetrical- it is clustered at one end

Question 7

what is a positive skew (2)

Answer 7

the long tail is on the positive side of the peak (right) and most of the distribution is on the left
eg. lots of low marks on a test
-order of central tendencies (right to left):
mode->median->mean

Question 8

what is a negative skew (2)

Answer 8

the long tail is on the negative side of the peak (left) and most of the distribution is on the right
eg. lots of high marks on a test
-order of central tendencies (left to right):
mean->median->mode