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Practical skills assessed in a written examination

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Question 34

During an ecology field experiment, a group of students investigates the foraging preferences of hoverflies (Syrphidae) when presented with three different colours of artificial flowers: blue, yellow, and white.

The students place ten artificial flowers of each colour randomly across a meadow and record the total number of hoverfly visits to each flower colour over a four-hour observation period.

The recorded visits are shown in the table below:

Flower ColourNumber of hoverfly visits
Blue65
Yellow112
White63

The null hypothesis formulated by the students is that there is no preference for flower colour, meaning hoverflies visit each colour with equal frequency.

a.

Calculate the χ2 \chi^2\,χ2 value for the students' data using the formula:

χ2=∑(O−E)2E \chi^2 = \sum \frac{(O - E)^2}{E} χ2=∑E(O−E)2​
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b.

The critical value for χ2 \chi^2\,χ2 at the 5% significance level (p=0.05p = 0.05p=0.05) for this test is 5.991. Discuss what can be concluded from this comparison.

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Practical skills assessed in a written examination Questions

  1. A Level
  2. /Biology
  3. /Practical skills assessed in a written examination