Comparisons Of Central Tendency Averages

Question 1

Mean

Answer 1

Takes jn all data values so it can be easily influenced by high or low values , thus susceptible to outliers

Question 2

Median , mode , midrange

Answer 2

Less sensitive to outliers
Median good and decent if values not relative to mean
Mode only used for high frequency data
Midrange is also susbcitbke to outliers don’t use , assumes data symmetrical!!!

Question 3

Calculating median from frequency table

GROUPED DATA

Answer 3

Remember if even frequency it will be an average of both middle values need to remember this

2) IF ITS GROUPED THEN JUST DIVIDE BY 2 DONT ADD ONE

Question 4

How to compare box plot

Answer 4

1) median , higher median means higher average
2) IQ range, shows how much or less spread out data is
3) range

Question 5

Standard deviation for grouped values ?

Answer 5

USE MIDPOINT AS VALUE FOR X THE

= f* x^2 then do the rest

Question 6

Outliers

Answer 6

2 plus minus SX from mean or

1.5 IQR from quartiles

Question 7

Scatter diagrams IMPORTSNT about correlation

Answer 7

Correlation does not imply causation

Question 8

How to better data

Answer 8

Clean it , use different sample techniques with better ways of doing em , better collecting method

Also if straitifying straitify by more regions etc

Question 9

Remember if they don’t already give class width what you have to do for adjustment?

Answer 9

Round it by upper bounds and ADJUST !