State whether the following represent cases of estimation or hypothesis testing.

a. A random sample of quadrats in Olympic National Forest is taken to determine the average density of Ensatina salamanders.

b. A study to determine whether there is extrasensory perception (ESP) is carried out by counting the number of cards guessed correctly by a subject isolated from a second person who is drawing cards randomly from a normal card deck. The number of correct guesses is compared with the number we would expect by chance if there were no such thing as ESP.

c. A trapping study measures the rate of fruit fall in forest clear-cuts.

d. An experiment is conducted to calculate the optimal number of calories per day to feed captive sugar gliders (Petaurus breviceps) to maintain normal body mass and good health.

e. A clinical trial is carried out to determine whether taking large doses of vitamin C benefits the health of advanced cancer patients.

f. An observational study is carried out to determine whether hospital emergency room admissions increase during nights with a full moon compared with other nights.