# Calculating summary statistics from a grouped frequency table

I can calculate the median, mode and range from a grouped frequency table.

# Calculating summary statistics from a grouped frequency table

I can calculate the median, mode and range from a grouped frequency table.

## Lesson details

### Key learning points

- The median and mode are measures of central tendency.
- The range is a measure of the spread of the data.
- Calculating these from a grouped frequency table may be easier when the data set is very large.

### Common misconception

That the interval widths need to be constant, or conversely that they can be anything.

If interested in people's ages it may be that decades makes sense once over 30 but that significant ages such as 16, 18 and 21 should form boundaries, depending on context. Encourage critical thinking for data with unequal intervals.

### Keywords

Interval - An interval is all the values between two points.

Modal class - The modal class is the interval, or group of values, with the highest frequency in a data set.

Median class - The median class is the class which contains the central (middle) datum when the data are in numerical order.

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Video

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## Starter quiz

### 6 Questions

mean -

6

median -

3

mode -

2

range -

17

## Exit quiz

### 6 Questions

modal class -

the interval with the highest frequency in a data set

median class -

the interval which contains the central datum in an ordered data set

mode -

the most frequent data value in a data set

a -

4

b -

20

c -

35

median class -

$$90 \leq x < 100 $$

modal class -

$$100 \leq x < 105 $$