Descriptive Statistics

Question 1

descriptive statistics

Answer 1

use of tables, graphs, summary stats to analyse data
e.g. bar chart, histogram

Question 2

measures of central tendency

Answer 2

any measure which calculates an AVERAGE value within a set of data

Question 3

mean

Answer 3

total of all values in a data set divided by the number of values

Question 4

mean: strength

Answer 4

makes use of all values
good for interval data

Question 5

mean: weakness

Answer 5

influenced by outliers, therefore can be unrepresentative

Question 6

median

Answer 6

arrange data from lowest to highest then find the central value

Question 7

median: strength

Answer 7

not affected by outliers
good for ordinal data

Question 8

median: weakness

Answer 8

not as sensitive as mean
does not use all data

Question 9

mode

Answer 9

most frequently occurring value in data set

Question 10

mode: strength

Answer 10

useful for nominal data

Question 11

mode: weakness

Answer 11

not useful when there are several modes

Question 12

measures of dispersion

Answer 12

any measure that calculates the variation in a set of data

Question 13

range

Answer 13

highest score minus lowest score

Question 14

range: strength

Answer 14

easy to calculate

Question 15

range: weakness

Answer 15

affected by extreme values
does not use all data

Question 16

standard deviation

Answer 16

square root of the variance
- low SD means more data is clustered close to the mean, therefore there is less data spread

Question 17

standard deviation: strength

Answer 17

precise measure
all data values used

Question 18

standard deviation: weakness

Answer 18

difficult to calculate
affected by extreme values