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.
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.
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.
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).
Lesson 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 -
$$100 \leq x < 105 $$