An article in the Journal of Applied Physiology ["Humidity Does Not Affect Central Nervous System Oxygen Toxicity" (2001, Vol. 91, pp. 1327-1333)] reported that central nervous system (CNS) oxygen toxicity can appear in humans on exposure to oxygen pressures >180 kPa. CNS oxygen toxi- city can occur as convulsions (similar to epileptic seizures, grand mal) and loss of consciousness without any warning symptoms. CNS oxygen toxicity is a risk encountered in sev eral fields of human activity, such as combat diving with closed-circuit breathing apparatus and diving with mixtures of nitrogen and oxygen (nitrox) or nitrogen, oxygen, and helium (trimix) in sport and professional diving to depths >30 m. The risk of oxygen toxicity is always considered when deep diving is planned. The data shown below demonstrate shortened latencies in a dry atmosphere ( <10% humidity) in 11 rats at O, of 507 kPa. The data collected are as follows:

(a) Given the above probability plot of the data, what is a logical assumption about the underlying distribution of the data?

(b) Explain why this check of the distribution underlying the sample data is important if we want to construct a confi- dence interval on the mean.

(c) Find the 95% confidence interval for the mean.

(d) Explain why this check of the distribution underlying the sample data is important if we want to construct a confi- dence interval on the variance.

(e) Find the 95% confidence interval for the variance.