Data summaries and probability
Strand: statistics reasoning
Suggested duration: 30 minutes
Status: New instructional practice, not an official TSIA2 item or score predictor.
Learn — guided worked example
Problem: For 2, 4, 4, 10, find the mean and median.
- Mean: (2 + 4 + 4 + 10) ÷ 4 = 5.
- Median: middle two values are 4 and 4, so (4 + 4) ÷ 2 = 4.
- The mean is affected more by the high value 10.
Think about it: Which quantity or operation tells you that the answer is reasonable? Explain in one sentence.
Practice — choose one answer
Work each problem before checking the explanations. The four choices are independent practice, not an official adaptive test.
1. Find the mean of 3, 5, 7, and 9.
- A. 5
- B. 6
- C. 7
- D. 24
2. Find the median of 12, 3, 8, 5, 9.
- A. 5
- B. 8
- C. 9
- D. 12
3. A bag contains 4 blue, 3 green, and 1 red marble. What is P(red)?
- A. 1/8
- B. 1/4
- C. 1/3
- D. 1/2
4. A fair six-sided die is rolled. What is P(even)?
- A. 1/6
- B. 1/3
- C. 1/2
- D. 2/3
Reflect
Which step was most difficult? Write a correction in your own words, then solve a similar problem without looking at the worked example.