Measures of Location and Spread

Question 1

mode

Answer 1

Occurs most often

Question 2

Median

Answer 2

The middle value when the data values are put in order

Question 3

How to calculate the mean normally?

Answer 3

x̄ = Σx /n

(The mean = The sum of the data values / the number of data values)

Question 4

How to calculate the mean when data is given in a cumulative frequency table?

Answer 4

x̄ = Σxf / Σf

(The mean = the sum of the products of the data values and their frequencies / the sum of the frequencies)

Question 5

What is Variance?

Answer 5

Shows how spread out the data is

Question 6

Basic Formula of Variance

Answer 6

σ² = (Σx²/n) - (Σx/n)²

Question 7

Sxx =

Answer 7

= Σx² - [ (Σx)² /n ]

Question 8

Standard deviation

Answer 8

Given in formula book

Question 9

Mean coding

Answer 9

x̄ = (ȳ - b) /a

Question 10

Standard deviation coding

Answer 10

σx = σy / |a|