Experiments: Calculations

Question 1

How do you work out mean?

Answer 1

Add all the raw scores and divide by how many data points there are

Question 2

How do you work out mode?

Answer 2

Most common number appearing

Question 3

How do you work out median?

Answer 3

Middle number, organise data in ascending order and find the middle number. If none, find the mean of the two middle numbers

Question 4

How do you work out range?

Answer 4

Subtract the smallest number from the largest number. This gives a measure of dispersion

Question 5

What is dispersion?

Answer 5

How far away each data point is from the mean

Question 6

How do you work out variance?

Answer 6

1. Find the mean
2. Subtract the mean from each data point (number)
3. Square the numbers you get
4. Add all those new answers up
5. Divide that number by the number of data points

Question 7

How do you work out standard deviation?

Answer 7

Square root the variance

Question 8

What is an advantage of using median?

Answer 8

Discounts outliers so not skewed

Question 9

What is an advantage of using mode?

Answer 9

-Easy to calculate
-Always a whole value
-Can be done with qualitative data

Question 10

What is an advantage of using range?

Answer 10

-Easy to calculate
-Shows the spread between the min and max values

Question 11

What is an advantage of using variance?

Answer 11

-Takes into account all data variables in the set
-Less likely to be affected by outliers

Question 12

What is an advantage of using standard deviation?

Answer 12

-Same units as original measure
-Easy to calculate if the variance is already done

Question 13

What is an advantage of using mean?

Answer 13

Involves all the data

Question 14

What is a disadvantage of using mean?

Answer 14

-Includes outliers which can skew result
-Can give decimal figures

Question 15

What is a disadvantage of using median?

Answer 15

-Does not include all data collected
-May be a decimal figure

Question 16

What is a disadvantage of using mode?

Answer 16

-There can be no or more than one mode
-Doesn’t include all data points

Question 17

What is a disadvantage of using range?

Answer 17

-Does not show if the spread is even
-Can be skewed by outliers

Question 18

What is a disadvantage of using variance?

Answer 18

-More time consuming to calculate
-Not in the same units as original measure

Question 19

What is a disadvantage of using standard deviation?

Answer 19

Takes into account extreme outliers

Question 20

What will the curve on a graph look like if there is low standard deviation?

Answer 20

If the data is not very spread out from the mean, the curve will be thin

Question 21

What will the curve on a graph look like if there is high standard deviation?

Answer 21

If the data is more spread out, the curve will be wider