Sarah Wysocki
Statistics Project
A social studies teacher posted the grades for 30 of her student for the final test of the year.
The scores are: 82, 76, 66, 95, 95, 67, 94, 78, 69, 88, 97, 59, 77, 70, 73, 67, 78, 56, 73, 92, 81, 92, 95, 90, 73, 87, 75, 88, 93, and 71
Find Quartile 1 and Quartile 3, Median, Lower and Upper Extremes and then Construct a box and whisker plot to represent the
data given.
Median
First, rewrite grades from lowest to highest.
Second, mark out from the outside to the inside.
 Even data= you will end up with two grades left
Scores in order: 56,59,66,67,67,69,70,71,73,73,73,75,76,77,78,78,81,82,87,88,88,90,92,92,93,94,95,95, 95, 97
Third, calculate to find median of the 30 grades.
78 + 78 156
=
= 78
2
2
Median=78
Quartile 1
First, rewrite grades from lowest to highest.
Second, start eliminating numbers starting with the first half of the grades.
Scores in order: 56,59,66,67,67,69,70,71,73,73,73,75,76,77,78,78,81,82,87,88,88,90,92,92,93,94,95,95, 95, 97
Quartile 1= 71
Quartile 3
First, rewrite grades from lowest to highest.
Second, start eliminating numbers starting with second half of the grades.
Scores in order: 56,59,66,67,67,69,70,71,73,73,73,75,76,77,78,78,81,82,87,88,88,90,92,92,93,94,95,95, 95, 97
Quartile 3= 92
Upper and Lower Extremes
First, rewrite grades from lowest to highest.
Scores in order: 56,59,66,67,67,69,70,71,73,73,73,75,76,77,78,78,81,82,87,88,88,90,92,92,93,94,95,95, 95, 97
Second, find the highest value (upper) and the lowest value (lower) of the grades.
Upper Extreme=97 Lower Extreme=56
Now, with the Data calculated and collected you can now construct the box-and-whiskers plot:
Upper
Extreme
97
Lower
Extreme
56
dd
dd
Quartile 1
71
dd
Median
78
dd
Quartile 3
92
dd