Statistics Year 1 Unit 2

Question 1

What is better, range or IQR?

Answer 1

IQR

Question 2

What is variance?

Answer 2

A calculation of spread using every piece of data

Question 3

Standard deviation is the ____ _____ of varience

Answer 3

square root

Question 4

Does the mean of squares = the square of means?

Answer 4

no

Question 5

Variance =

Answer 5

mean of squares - square of means

Question 6

Symbols for variance and standard deviation

Answer 6

σ for standard deviation and σ^2 for variance

Question 7

What does an x with a bar on top mean?

Answer 7

The mean of x

Question 8

Variance equation

Answer 8

((Σ(x^2))/n) - ((Σx)/n)^2

Question 9

Standard deviation equation

Answer 9

root(((Σ(x^2))/n) - ((Σx)/n)^2)

Question 10

How does coding by +/- effect mean?

Answer 10

if y = x - a, then mean(y) = mean(x) - a

Question 11

How does coding by x/’/. effect mean?

Answer 11

if y = x/b, then mean(y) = mean(x)/b

Question 12

How does coding by +/- effect standard deviation?

Answer 12

if y = x - a, then xσ^2 = yσ^2

Question 13

How does coding by x/’/. effect standard deviation?

Answer 13

if y = x/b, yσ^2 = (xσ^2)/b

Question 14

Another way to write variance

Answer 14

variance = (sxx)/n