17 Mercury levels in wading birds. According to a University of Florida wildlife ecology and conservation researcher, the average level of mercury uptake in wading birds in the Everglades has declined over the past several years. ( UF News , December 15, 2000). Ten years ago, the average level was 15 parts per million.

a. Give the null and alternative hypotheses for testing whether the average level today is less than 15 ppm.

b. Describe a Type I error for this test.

c. Describe a Type II error for this test.