Unit 8: Confidence

Question 1

Why do we need a Margin of Error?

Answer 1

There is variability in random selection or random assignment.

Question 2

Two ways to reduce the Margin of Error.

Answer 2

-Decrease the confidence level
-Increase the sample size (which decreases the standard deviation of the statistic)

Question 3

Why is checking for the Random Condition important?

Answer 3

Without Randomization, we would not have any inference to a population (aka random sampling) or cause and effect (random assignment), making confidence intervals useless.

Question 4

Why is checking for the Normal Condition important?

Answer 4

Without Normal Distribution, we wouldn’t be able to center our intervals around our point estimate. If the sampling distribution were skewed, the capture rate would not be accurate.