in a random sample of 12 residents of the state of montana, the mean waste recycled per person per day was 2.2 pounds with a standard deviation of 0.84 pounds. determine the 90% confidence interval for the mean waste recycled per person per day for the population of montana. assume the population is approximately normal.step 1 of 2 : find the critical value that should be used in constructing the confidence interval. round your answer to three decimal places.