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.
Oocyte maturation in certain species of frogs
Boreal forests, such as this one in Siberian Russia, are dominated by a few species of conifer trees
Species-rich Sonoran Desert landscape.
The Eastern Banjo Frog is a common frog species across eastern Australia.
A Healthy Body Weight
Gray Morris's Calculate with Confidence, Canadian Edition, 2nd Edition