Data on the reaction times of 80 participants in a psychology experiment conducted in Germany is displayed in a histogram. The total area of all bars in the histogram is 80 square units. One bar, representing the class interval 0.2 ≤ t

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Question

Data on the reaction times of 80 participants in a psychology experiment conducted in Germany is displayed in a histogram. The total area of all bars in the histogram is 80 square units. One bar, representing the class interval 0.2 ≤ t < 0.4 seconds, has an area of 12 square units. What percentage of participants had reaction times in this interval?

Accepted Answer

15% — Award 1 mark for correct calculation: percentage = (12 ÷ 80) × 100 = 15%. A is incorrect — this confuses area with percentage directly. C is incorrect — this would require an area of 16 square units. D is incorrect — this results from dividing 12 by 180.

Answer

12%

Answer

6.7%

Answer

20%

Answer

15%

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