Long-distance runners have contended that moderate exposure to ozone increases lung capacity. To investigate this possibility, a researcher exposed 12 rats to ozone at the rate of two parts per million for a period of 30 days. The lung capacity of the rats was determined at the beginning of the study and again after the 30 days of ozone exposure. The lung capacities (in mL) are given here.

a. Is there sufficient evidence to support the conjecture that ozone exposure increases lung capacity? Use α = .05. Report the p-value of your test.
b. Estimate the size of the increase in lung capacity after exposure to ozone using a 95% confidence interval.
c. After completion of the study, the researcher claimed that ozone causes increased lung capacity. Is this statement supported by this experiment?

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Rat 1 2 3 5 6789 10 1 12 Before exposure 8.7 7.9 8.3 84 9.2 9.1 82 81 89 82 89 7.5 After exposure 94 9.8 99 10.3 8.9 88 9.8 82 94 9.9 122 9.3