Grouped Frequency tables

Question 1

What are grouped frequency tables?

Answer 1

Frequency tables which group data into classes.

Question 2

How do you work out the modal class in a grouped frequency table?

Answer 2

The class with the highest frequency.

Question 3

How do you work out the class with the median in a grouped frequency table?

Answer 3

Calculate the total frequency. Divide frequency by two and find the class which contains it.

Question 4

How do you work out the mean (estimate) in a grouped frequency table?

Answer 4

Add an extra column called Mid-Interval value. This is the middle value between the two values of a class.
For example:
5 < h < 10, the Mid-Interval value is 7.5
Add another extra column called Mid-Interval x Frequency. Add up this column and divided this by the total frequency.

Question 5

How do you work out the range in a grouped frequency table?

Answer 5

The biggest class boundary - smallest class boundary