Statistics Worksheet
Mr. Almeida
1. The four houses of Hogwarts recently took a Psychology exam. Use these data to
determine important statistics to the nearest hundredth.
Ravenclaw Hufflepuff Slytherin Gryffindor
52
44
44
42
50
42
38
48
50
54
46
42
56
28
38
38
40
50
44
40
46
42
52
46
36
42
32
46
54
34
48
34
46
32
44
48
50
50
30
44
40
32
30
46
36
56
58
50
42
40
54
40

Measures of Central Tendency
i. Mean
1. Ravenclaw
2. Hufflepuff
3. Slytherin
4. Gryffindor
ii. Median
1. Ravenclaw
2. Hufflepuff
3. Slytherin
4. Gryffindor
iii. Mode
1. Ravenclaw
2. Hufflepuff
3. Slytherin
4. Gryffindor

Measures of Variability
i. Range
1. Ravenclaw
2. Hufflepuff
3. Slytherin
4. Gryffindor
2. Is determined that the Standard Deviations for test scores in each house are as follows:
 Ravenclaw: 4
 Hufflepuff: 3
 Slytherin: 6.5
 Gryffindor: 4.1
Which house as the widest variation in test scores?
Using the means (averages) you just calculated for each house, interpret what these
standard deviations represent for Hufflepuff and Slytherin (compare/contrast the two).
3. It is determined that the average test score for ALL Hogwarts students is a 44, with a
standard deviation of 4.
 Draw (you can use a program like Microsoft Paint) a normally distributed curve.

Using the mean and SD, label the test scores at μ(mean/average), and at 1σ, 2σ,
and 3σ, and at -1σ, -2σ and -3σ.

Answer the following questions:
i. What percentage of Hogwarts students earned a score between 40 and a
48?
ii. What percentage of Hogwarts students earned a score of 44 or greater?
iii. What percentage of Hogwarts students earned a score of less than 36?
iv. What percentage of Hogwarts student earned a score of 40 and above?