Measure Of Dispersion

Question 1

What is measures of dispersions

Answer 1

• where a set of data can be described in terms of how dispersed or spread out the data items are

Question 2

Range

Answer 2

• the distance between the top and bottom values in a set of data
• once you have the difference between the two numbers it is customary to add 1
• range is helpful as a further method you describing the data

Question 3

Standard deviation

Answer 3

• ## more precise method of expressing dispersion

Question 4

How would you calculate the standard deviation

Answer 4

I Would calculate the standard deviation by completing the following steps:
- I would first calculate the mean of the data set
- I would take the mean away from each score in the data set
- square each difference
- add together each of the squared differences
- divide this by the n - 1
- lastly find the square root of this value to get the standard deviation

Question 5

A strength of standard deviation

Answer 5

• it’s more precise and informative measure of dispersion than the range
• less affected by anomalous results than range scores

Question 6

A weakness of standard deviation

Answer 6

• can only be used if the data set is normally distributed and not skewed
• can only be used when data is ordinal level or above

Question 7

A strength of range

Answer 7

• easy to calculate

Question 8

A weakness of range

Answer 8

-affected by extreme values
- doesn’t take into account of the distribution of the numbers