Starter quiz
- A statistical summary sums up the features of a data set. It may contain an ______ which measures the central tendency. It may also contain the range which measures the spread.
- 'average' ✓
The mode of this data set is ______.- '23' ✓
- The range of this data set is ______.
- '7' ✓
- The median of this data set is ______.
- '25' ✓
- The mean of this this data set is ______.
- '26' ✓
This table represents the number of cars in 40 households. The mean number of cars per household is ______ cars.- '1.25' ✓
Exit quiz
The modal group in this stem and leaf diagram is __________.- 30 km - 39 km
- 40 km - 49 km ✓
- 50 km - 59 km
- 60 km - 69 km
-
- The modal distance is ______ km.
- '42 ' ✓
- The range of the data shown on this stem and leaf diagram is ______ km.
- '34' ✓
The total of the first row of leaves is ______ kg.- '256' ✓
Sam and Andeep draw a back-to-back stem and leaf diagram to compare their classes' scores in a quiz. Match the summary statistic for each class with its value.- Sam's class: range⇔39 ✓
- Sam's class: mode⇔31 ✓
- Sam's class: median⇔54 ✓
- Andeep's class: range⇔34 ✓
- Andeep's class: mode⇔42 ✓
- Andeep's class: median⇔42.5 ✓
Calculate the mean mass (to 2 decimal places) of the data represented in this stem and leaf diagram. The totals for each row have been calculated already.- '80.64 kg' ✓
Worksheet
Presentation
Video
Lesson Details
Key learning points
- The range can be calculated from a stem and leaf diagram.
- The mode can be calculated from a stem and leaf diagram.
- The median can be calculated from a stem and leaf diagram.
- Although possible, the mean is very time consuming to calculate.
Common misconception
You can only find the median class from a stem-and-leaf diagram.
The data is organised into intervals based on place value. However the full data is still available so the middle value(s) can still be found. The diagram is a form of an ordered list so previous methods for finding the median still apply.
Keywords
Stem and leaf diagram - A stem and leaf diagram is a systematic way to organise and represent numerical data, by splitting each value into a stem and a leaf.
Mean - The (arithmetic) mean for a set of numerical data is the sum of the values divided by the number of values. It is a measure of central tendency representing the average of the values.
Median - The median is the central (middle) piece of data when the data are in numerical order.
Mode - Mode is the most frequent value. It is a measure of central tendency representing the average of the values.
Range - The range is a measure of spread. It is found by finding the difference between the two extreme points; the lowest and highest values.