Dealing with data (moodle audio book) 9 in book

Question 1

What is ratio data?

Answer 1

Data on a continuous scale with no negative values and where 0 indicates an absence of quantity. On this scale the
distance between any two consecutive whole numbers are always equal intervals. This is the highest form of measurement and all
four basic mathematical operations are possible (add, minus, multiply and divide).

E.g weight, heart beats

Question 2

What is interval data?

Answer 2

Interval and ratio data are treated in the same way for the purpose of statistical analysis although there are subtle
differences between the two.
The main difference is that with interval data you can have a scale with minus figures. If we were measuring a patients temperature in degrees Celsius this would be interval data. On this scale the distance between any two consecutive whole numbers are always equal intervals. The four basic mathematical operations are possible.

Question 3

What is ordinal data?

Answer 3

Ordinal values have a sense of relative position and are typically subjective interpretations. For example on a Likert
scale there may be 5 categories from strongly disagree to strongly agree. So ordinal values can be ranked but the intervals between
the values are not necessarily equal; imagine first, second, third and fourth place results in a race - the gaps between these positions
are unlikely to be equal and could be very different. On an ordinal scale there is order, that is 4 is greater than 2, but you can’t say
how much greater.

Question 4

What is nominal data?

Answer 4

Nominal or Categorical Data: Nominal data are presented as discrete categories with no order. For example, male / female. Nominal
data is used with frequency counts as shown in the diagram below.

Question 5

There are three different ways to state the average or central tendancy, what are they?

Answer 5

Mean, median and mode

Question 6

What is the mean?

Answer 6

Mean: Here you add all the values together and divide by the number of values.

Question 7

What is the median

Answer 7

Median: Here you arrange the values in ascending order and pick out the middle value.

Question 8

What is the mode?

Answer 8

Mode: Here you need to find the most common / frequently occurring value in the list.