Question 1 (16 marks)

To study the effect of the ecological impact of malaria, researchers in California measured the effect of malaria on what distance an animal could run in 2 minutes. They used a sample of a local lizard species,Sceloporis occidentalis, collected in the field. They selected 17 lizards from those found to be infected with the malarial parasitePlasmodium mexicanumand 17 lizards found not infected. The distance each lizard could run in a time limit of 2 minutes was recorded in a controlled environment. The data is in an Excel file,"lizard.xlsx"

a)Does this design use paired data or unpaired data?

b)Determine if there is a decrease in the mean distance ran due to malaria by

• computing a 90% confidence interval, and
• conducting a test of significance at a significance level of 5%.

Show all details of your working.

c)Is the conclusion from the confidence interval calculation above the same as the conclusion of the test above? Explain why or why not.

Infected Uninfected 30 39 22 38 27 45 20 44 24 33 22 33 30 27 23 46 30 29 25 32 17 36 24 44 15 35 26 38 26 41 15 39 17 40