Probability and Statistics — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Test scores 80, 85, 90, 95, 100 have a mean of 90.
The sum four hundred fifty divided by five scores yields an average of ninety.
2. Heights 50, 52, 54, 56, 58 inches have a median of 54.
The third value of five ordered numbers is the median, here fifty-four.
3. Minutes read: 20, 25, 25, 30, 35. The mode is 25.
Twenty-five is the only repeated value, appearing twice in the entire list.
4. Test scores 70, 75, 80, 85, 90 have a range of 20.
The maximum ninety minus minimum seventy gives a range of twenty.
5. Sets of 6, 8, 10, 12 books read have a mean of 9.
The total thirty-six divided by four entries equals an average of nine.
6. Quiz scores 8, 9, 10, 10, 10 have a mode of 10.
Ten appears three times while other scores appear only once each.
7. Steps walked 1000, 2000, 3000, 4000 have a range of 3000.
The maximum four thousand minus minimum one thousand equals three thousand.
8. Numbers 4, 6, 8, 10 have a median of 7.
With even count, the middles six and eight average to seven.
9. Scores 60, 70, 80, 90, 100 have a mean of 80.
The total four hundred divided by five scores gives an average of eighty.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Mean of 5, 10, 15
→ 10
10
Median of 2, 4, 6, 8, 10
→ 6
6
Mode of 7, 7, 8, 9
→ 7
7
Range of 12, 18, 25
→ 13
13
Each list yields exactly one of the four results listed on the right.