In order to determine the average amount of unburned hydrocarbons pro duced by a particular brand of carburetor (adjusted in what is believed to be the optimal way), a random sample of 35 carburetors was taken, and the amount of unburned hydrocarbons recorded. The three largest and three smallest values were 1.7, 2, 4.1 and 7.9, 8.2, 9.3. The average amount was computed to be 5.7 with a sample standard deviation of 0.9. The manufac turer suspects that the distribution of unburned hydrocarbons is not nor mal.
(a) Construct an 88% confidence interval for the average amount of unburned hydrocarbons for the entire population of this brand of car buretor.
(b) Construct an 88% prediction interval for the amount of unburned hydrocarbons produced by the next carburetor tested.
(c) Construct an interval that with 90% confidence will cover 90% of the population.