Practice Spread vs Center in Statistics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
Center describes where the 'middle' of data lies; spread describes how far data extends from that center.
Two pizza delivery services both average 30-minute delivery (same center). But Service A ranges 28-32 minutes, while Service B ranges 10-50 minutes. Same center, wildly different spread. You'd trust A for consistent timing.
Example 1
mediumTwo machines fill bottles. Machine A fills: 500, 502, 498, 501, 499 mL. Machine B fills: 490, 510, 480, 520, 500 mL. Both have a mean of 500 mL. Which machine is more reliable?
Example 2
mediumDataset A: {10, 10, 10, 10, 10}. Dataset B: {2, 6, 10, 14, 18}. Compare their centres and spreads.
Example 3
mediumA restaurant's lunch wait times (minutes) — Week 1: 5, 6, 5, 7, 5. Week 2: 3, 10, 4, 8, 3. Find the mean and range for each week and explain which week had more predictable service.
Example 4
mediumTwo classes both have median score 75. Class A scores are 72, 74, 75, 76, 78. Class B scores are 60, 70, 75, 80, 90. Which class has greater spread, and which class seems more consistent?