Location, Spread, Coding and Representation

Question 1

Mean

Answer 1

Ex / n or Efx / Ef

Question 2

Describe IQR

Answer 2

IQR = Q3 - Q1. It ignores extremes

Question 3

Variance

Answer 3

Mean of the squares - square of the means

Question 4

Linear coding, if y = ax+b

Answer 4

Mean = a xbar + b
Variance = a^2 x variance

Question 5

Frequency density

Answer 5

frequency/class width

Question 6

What is PMCC

Answer 6

PMCC is between -1 and 1, measures strength and +- of correlation

Question 7

Exponential/non linear models when y = ab^x

Answer 7

lny = lna + xlnb

Question 8

Exponential/non linear models when y = ax^n

Answer 8

lny = lna + nlnx