1. Nerve impulse rate, in meters/second, was measured in 49 Pacific banana slugs. The sample mean was 44.6 m/s, with a standard deviation of 18.1 m/s.

a. What must be assumed prior to using this information to calculate a t confidence interval?

b. Use the information provided above to calculate a 95% confidence interval. You will have to use your calculator's "TInterval" on the "stats" setting because JMP requires the individual values, which are not available.

c. How many degrees of freedom are associated with the interval you calculated in part b?

d. Provide a one-sentence interpretation of your interval

e. If a future study aims to estimate the mean with a standard error of no more than 2.0 m/s, what sample size should be used?

2. Only one of the confidence interval interpretations below is correct. Identify which is correct. For each incorrect interpretation, explain why that interpretation is not correct.

a. We can be 95% confident that the body temperatures of all healthy human adults are between 97.8 and 98.7 degrees Fahrenheit.

b. We can be 95% confident that the mean body temperature of 45 healthy human adults is between 97.8 and 98.7 degrees Fahrenheit.

c. There is a 95% probability that the mean body temperature of healthy human adults is between 97.8 and 98.7 degrees Fahrenheit.

d. We can be 95% confident that the mean body temperature among all healthy human adults is between 97.8 and 98.7 degrees Fahrenheit.