Question 8.77

77. Lead Contamination in Trout. The Washington State Department of Ecology reported that the mean lead contamination in trout in the Spokane River is 1 part per million (ppm), with a standard deviation of 0.5 ppm.10 Suppose a sample of trout has a mean lead contamination of . Assume that .

  1. Determine whether the requirements are met for constructing the interval for .
  2. Construct a 95% confidence interval for , the population mean lead contamination in all trout in the Spokane River.
  3. Interpret the confidence interval.

8.1.77

(a) and the population standard deviation is known. (b) (0.902, 1.098) (c) We are 95% confident that μ, the population mean lead contamination for all trout on the Spokane River, lies between 0.902 ppm and 1.098 ppm.