To determine the possible effect of a chemical treatment on the rate of seed germination, 250 chemically treated seeds and

325 untreated seeds were sown. It was found that 220 of the chemically treated seeds and 273 of the untreated seeds germinated. Let p1 be the proportion of the population of all chemically treated seeds that germinate, and let p2

be the proportion of the population of all untreated seeds that germinate. Find a 99% confidence interval for

p1- p2 . Then find the lower limit and upper limit of the 99% confidence interval.

Carry your intermediate computations to at least three decimal places. Round your responses to at least three decimal places. (If necessary, consult a list of formulas.)