3VL Measures of dispersion:

Question 1

1 quartile

Answer 1

viertel 1/4 quarter

Question 2

1 quintile

Answer 2

1/5 one fifth

Question 3

1 decentile

Answer 3

1/10 one ten

Question 4

1 percentile

Answer 4

1/100 one over one hundred

Question 5

Name Measures of Dispersion

Answer 5

1. Range
2. Interquartile range (IQR)
3. Standard Deviation and variance

Question 6

What does Range show?

Answer 6

The Range is simplest way of showing the variability

Question 7

Formula of Range

Answer 7

Max-min

Question 8

What are disadvantages of Range?

Answer 8

The range does not take into account
the data structure

Question 9

Formula of IQR

Answer 9

Q3-Q1

Question 10

What is IQR compering with range?

Answer 10

Range only distance between min and max but IQR is distance of the middle 50% of your observations

Question 11

What does IQR represents?

Answer 11

IQR is representative of the central grouping of the data set

Question 12

Advantage of IQR

Answer 12

Not affected by extreme values

Question 13

How to find IQR?

Answer 13

1. Find median (Q2)
2. Exclude the mean
3. Find mean with remaining values on
   both sides from first mean (find Q1 and Q3)
4. Q3-Q1=IQR

Question 14

What is Standard Deviation?

Answer 14

mean of all squared deviations in the dataset

Question 15

What is deviation?

Answer 15

amount by which a value differs from the mean

Question 16

Describe steps for calculating Standard Deviation

Answer 16

1. Find the mean
2. Find the distance of each value from the mean
3. Square the deviations
4. Sum up all squared deviations
5. Divide by N
6. Take the square root of the result

Question 17

Formula of Standard Deviation

Answer 17

Check notes

Question 18

How to interpretate Standard Deviation?

Answer 18

On average a value deviates by (SD) from the mean.
Change SD by calculated number

Question 19

Symbol of Standard deviation

Answer 19

SD or S

Question 20

When to write higher and lower SD?

Answer 20

lower SD stands for less variability

Question 21

formula of variance

Answer 21

Squared standard Deviation or all steps of Standard deviation without last one

Question 22

When is it possible to compare standard deviations from different datasets?

Answer 22

2 constraints when it is possible:
1. If the datasets have the same unit of measurement (both = Euros)
AND
2. If there are the same number of observations (N/n) in the two datasets

Question 23

How to understand if variation is high in different datasets?

Answer 23

To understand whether variation is high in different datasets, one can compare it to the mean use Coefficient of variation (CV)

Question 24

Formula of CV (Coefficient of variation)

Answer 24

Check notes

Question 25

With what level data can CV be used?

Answer 25

CV can only be used for ratio level data and should not be used for interval level data

Question 26

What rule of thumb does CV have?

Answer 26

CV>1 rather high variability
CV<1 rather low variability