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Clover Experiment Groups


An experiment was conducted to determine the effects of fertilizer and bacteria on the growth of clover plants. The experiment consisted of 4 groups. All groups received the following treatments:

  • 1 pint of sand
  • 5 clover seeds
  • Equal amounts of water and sunlight

Each group then received various other treatments listed below:

  • Group A: 1 pint of fertilized soil
  • Group B: 1 pint of fertilized soil, rhizobium bacteria
  • Group C: 1 pint of unfertilized soil
  • Group D: 1 pint of unfertilized soil, rhizobium bacteria

The following data were collected (median height of plants measured in centimeters):

Time after planting Group A Group B Group C Group D
1 week 0.9 1.8 0.0 1.0
2 weeks 1.2 2.9 0.2 1.4
3 weeks 1.3 3.7 0.4 1.8
4 weeks 1.5 4.2 0.7 2.1

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Which set of groups should be compared against each other to determine the effect of the bacteria on clover height?


A & B v. C & D


A & D v. B & C


A & C v. B & D


All groups should be compared to each other.


No groups can be compared to determine the effect of bacteria on growth.