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

Quizplus · Accepted Answer

The confidence interval includes both negative and positive values, indicating uncertainty about the direction of the difference in means (A). The interval's range does not imply certainty about which species weighs more, only that there is a range of plausible values for the difference in means (B). A narrower confidence interval (like 90%) might exclude zero, suggesting a significant difference, but this depends on the actual calculation and is not guaranteed by the information given (C).

Suppose You Computed a 95% Confidence Interval for the Difference