Author Question: Suppose you computed a 95 confidence interval for the difference in mean weight between two species ... (Read 89 times)

jazziefee · **on:** Jul 24, 2018

Suppose you computed a 95 confidence interval for the difference in mean weight between two species of snakes in a large nature reserve (species 1 species 2), and your interval is 3.6 to 61.6 ounces. What can you conclude?
a. You cannot say, even with 95 confidence that the observed difference in sample means represents a real difference in the population means.
b. Because the interval extends so much further in the positive direction than the negative, the evidence suggests that species 1 weighs more than species 2 on average, but we can't say for sure.
c. If we were willing to use 90 confidence, we could say that the observed difference in the sample means represents a real difference in the population means.
d. All of the above.

Question 2

What does it mean for a confidence interval for the difference of two means to contain zero?
a. You are unable to say there is a difference in the population means.
b. Different samples could give results in either direction; completely above zero, completely below zero, or containing zero.
c. The confidence interval will contain some negative numbers and some positive numbers.
d. All of the above.