QWuestion 7.

The U.S. Department of Health and Human Services is interested in estimating the amount of uoride levels in drinking water in Idaho. They take 38 samples of drinking water in locations across the state and nd the average amount of uoride per liter of water is E = 0.63 mg. Suppose the Known population standard deviation of the amount of uoride per liter of water is a = 0.028 mg. Use this information to answer the questions below. a. Compute an 86% oondence interval for p, the average amount of uoride per liter of water in Idaho. Enter your smaller bound as the 'lower bound' and your larger bound as the 'upper bound.' Round your answers to at least five decimals if necessary Lower bound: 3 u: Upper bound: 3 u: b. Interpret the interval that you calculated in part a. We are === % condent that the average amount of uoride levels in '9 "' is ? V the upper and lower bounds of the interval. c. Suppose we were to decrease the condence level from 36% to 84% and compute a new oondenoe interval. IT all other valuesiquantities stayed the same, now muld he width oTthis new interval compare to the width of the interval computed in part a.? O A. "he new interval would be the same width Q B. "he new interval would be narrower @ 0. "he new interval would be wider O D. "here is not enough information provided to determine how this would affect the interval Width