Spread vs Center Statistics Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

medium
A 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.

Solution

  1. 1
    Step 1: Week 1 mean = 285=5.6\frac{28}{5} = 5.6 min, range = 7−5=27-5=2 min. Week 2 mean = 285=5.6\frac{28}{5} = 5.6 min, range = 10−3=710-3=7 min.
  2. 2
    Step 2: Same mean, but Week 1 has a smaller range (2 vs 7), so service was more predictable in Week 1.

Answer

Both weeks have mean 5.6 min. Week 1 (range 2) had more predictable service than Week 2 (range 7).
Predictability is about spread, not centre. Customers experience more consistent service when the range is small.

About Spread vs Center

Center describes where the 'middle' of data lies; spread describes how far data extends from that center.

Learn more about Spread vs Center →

More Spread vs Center Examples

Example 1 medium

Two machines fill bottles. Machine A fills: 500, 502, 498, 501, 499 mL. Machine B fills: 490, 510, 4

Example 2 medium

Dataset A: {10, 10, 10, 10, 10}. Dataset B: {2, 6, 10, 14, 18}. Compare their centres and spreads.

Example 4 medium

Two classes both have median score 75. Class A scores are 72, 74, 75, 76, 78. Class B scores are 60,

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