Stem and Leaf Plot
 Order data from smallest to largest
 Divide each data into stem and leaf
 Create plot
DATA: Scores on first exam for Precalculus
33
42
49
49
53
55
55
61
63
67
68
68
69
69
72
73
74
78
80
83
88
88
88
90
92
94
94
94
94
96
100
The Median is a number that separates the data
into two halves. Half of the data is above the
median and half of the data is below the median.
Calculating the median:
 Order the data from smallest to largest
If there are an odd number of data values:
1,
1,
3,
DATA:
5,
6,
7,
9
If there are an even number of data values:
1,
1,
3,
DATA:
5,
6,
7,
9,
9
Boxplot
We are interested in the amount of money a
student in this class spent on books for this
quarter.
Five Number Summary
Smallest Value _____
Quartile 1
_____
Median
_____
Quartile 3
_____
Largest Value _____
IQR = Interquartile Range = Q3 – Q1
The middle 50% of the data is between Q1 and
Q3.
IQR and Outliers
If a data value is more than 1.5* IRQ below Q1
or above Q3, it is considered to be an outlier.
Boxplot on Calculator
33
42
49
49
53
55
55
61
63
67
68
68
69
69
72
73
74
78
80
83
88
88
88
90
92
94
94
94
94
96
100