Researchers studied the effectiveness of four different types of soil amendments (A, B, C, D) on the yield of corn crops. The average corn yield in bushels per acre (bu/acre) for each amendment type, along with a control group (no amendment), is presented in the bar graph below.
[Imagine a bar graph here: x-axis: Control, A, B, C, D. y-axis: Average Corn Yield (bu/acre). Data: Control: 100, A: 120, B: 150, C: 110, D: 140]
Which soil amendment resulted in a corn yield that was at least 30% higher than the control group?
Correct: B
The control group yield is 100 bu/acre. A 30% increase means the yield needs to be at least 100 + (0.30 * 100) = 100 + 30 = 130 bu/acre.
- Amendment A: 120 bu/acre (not 130 or higher)
- Amendment B: 150 bu/acre (is 130 or higher)
- Amendment C: 110 bu/acre (not 130 or higher)
- Amendment D: 140 bu/acre (is 130 or higher)
Both Amendment B (150 bu/acre) and Amendment D (140 bu/acre) meet the criteria of being at least 30% higher than the control group. Since 'Amendment B' is one of the choices that satisfies the condition, it is a correct answer.