Math 1 · Unit 12 · Lesson 5 · part 3 of 4
Delia's fertilizers, and spread in different units
Delia tested three fertilizers on tomato seedlings, ten seedlings each, and measured the heights in...
Delia's fertilizers, and spread in different units
Delia tested three fertilizers on tomato seedlings, ten seedlings each, and measured the heights in centimeters after three weeks. Which fertilizer should she use? Compare the centers (which grows taller) and the spreads (which grows more evenly).
| fertilizer | median | mean | IQR | σ |
|---|---|---|---|---|
| A | 15 | 14.9 | 3 | 1.81 |
| B | 16.5 | 17.0 | 6 | 4.36 |
| C | 18.5 | 18.5 | 3 | 1.50 |
All three are roughly symmetric with no outliers, so the mean and σ are fair to use, and the median and IQR tell the same story. Fertilizer C has the highest center (mean 18.5 cm, against 14.9 and 17.0) and the smallest spread (σ 1.50, against 1.81 and 4.36). Recommend C: its seedlings grew tallest and most evenly. B grew taller than A on average but was the least consistent.