Question

The table shows the height of pea plants in centimeters after 6 weeks of growth. Each plant started at a height of 5 centimeters. Two planting soils were tested. Which statement BEST compares the mean growth percentage for the two sets of data?

Planting soil 1 plant height:
15, 10, 19, 17, 16, 12, 20, 22, 18, 35
Planting soil 2 plant height:
16, 17, 10, 12, 18, 17, 14, 15, 17, 23
A) Planting soil 1 growth percentage is approximately 14% more than planting soil 2 growth percentage.
B) Planting soil 2 growth percentage is approximately 14% more than planting soil 1 growth percentage.
C) Planting soil 1 growth percentage is approximately 50% more than planting soil 2 growth percentage.
D) Planting soil 2 growth percentage is approximately 50% more than planting soil 1 growth percentage.

Answer 1

C

Explanation:

First find the mean of each group. To do this we total the numbers and then divide by the number of measurements. There are 10 measurements for each.

Planting soil 1

15 + 10 + 19 + 17 + 16 + 12 + 20 + 22 + 18 + 35 = 184

184 / 10 = 18.4cm

18.4 / 5 cm = 368

368% growth

Planting soil 2

16 + 17 + 10 + 12 + 18 + 17 + 14 + 15 + 17 + 23 = 159

159 / 10 = 15.9

15.9 / 5 = 318

318% growth

The difference between the two plant percentage growths is 50%, with plant 1 being more than plant 2, so the answer is C.