Quartiles
What is the median of this data set?
3 5 7 8 9 10 10
8
What is the median of this (vertical) box plot?
(If you had 23 or 25, give yourself half points)
What is meant by minimum value?
What would be the range of this data set?
48 52 57 64 68 69 70 75 88
40
What is the median of this data set?
14 18 20 22 24 25 27 30
23
Draw a rough box plot and label;
Minimum
Lower Quartile
Median
Upper Quartile
Maximum
Correct Drawing (Slide 25)
What is the median of a data set?
What are the five things you need for the five number summary?
1. Lowest data
2. Median
3. Lower quartile
4. Upper quartile
5. Highest data
What is the lower quartile (LQ or Q1) of this odd-numbered data set?
5 8 11 12 13 16 18 19 20 22 25
11
What is the interquartile range of this box plot?
87 - 51 = 36
(Will accept any answers between 35 and 37)
What is the range of a data set? (ie. How do you calculate it?)
Biggest number - lowest number
What percentage of data sits within the Interquartile range?
50%
What is the upper quartile of this even-numbered data set?
32 35 38 38 39 41 44 48 49 50
48
Draw a box plot which has;
Lowest value 5
Lower quartile 15
Median 20
Upper Quartile 40
Maximum 50
Teacher will confirm answers
What is the interquartile range? (ie. how do you find it?)
Upper quartile - lower quartile
What is the interquartile range of the following data set?
27 30 31 33 34 37 38
7
Find the median, lower quartile and upper quartile of this data set.
10 13 14 15 15 16 19 20 21 25 26 28
Median: 17.5
Lower Quartile: 14.5
Upper Quartile: 23
Make THREE comparisons between the two box plots.
Discuss the median
Discuss the Interquartile range (or spread of data)
Discuss the maximum and/or minimum scores
What is an outlier?
Any data point which has a data point 1.5 x IQR lower than the Lower Quartile OR 1.5 x IQR greater than the Upper Quartile
(Half points if you just mentioned 1.5 x IQR)
75%