Stats Chapter2+3

Question 1

Continuous data

Answer 1

Values are presented in ranges (essentially in groups)

Question 2

Mode

Answer 2

Most common

Question 3

Median how to calculate (for discrete data)

Answer 3

n/2

• when not a whole number round up
• when a whole number find mid point of this value and the one above

Question 4

Median for continuous data

Answer 4

N/2 and keep value for calculation!!! Whatever it is

Then use interpolation
• find affected group
• bear in mind bounds

Question 5

Discrete data

Answer 5

Set values only

Question 6

Variance def

Answer 6

Average of squares of the differences

Question 7

Standard deviation

Answer 7

Square root of variance
Average deviation from the mean

0–

Question 8

Standard deviation equation

Answer 8

Square root of Ex^2/n - mean^2

Or

Square root of Ex^2/Ef - (Ex/Ef)^2

Question 9

IQR

Answer 9

Upper quartile- lower

Question 10

Coding

Answer 10

Where y values are used instead of x

Relationship is given in a ‘code’

Question 11

Frequency =

Answer 11

Class width x frequency density

Question 12

Quantitative

Answer 12

Numerical observations

Question 13

Qualitative

Answer 13

Non numerical observations

Question 14

Q1 how to find

Answer 14

N/4

Rules apply as with mediun

Question 15

Q3

Answer 15

3n/4

Question 16

xth percentile

Answer 16

Find value of x(n)/100

Question 17

Inter percentile range?

Answer 17

n%-m%

Question 18

Interpercentile range is also…

Answer 18

Interquartile range

75%-25%

Question 19

Variance equation

Answer 19

Efx^2/Ef -(Efx/Ef)^2

Question 20

Coding multiplying of dividing

standard dev

Answer 20

Does effect!!!

Question 21

Coding adding and subtracting

standard dev

Answer 21

No- doesn’t change