Chapter 10 - Sampling Distributions and Confidence Intervals for Proportions Flashcards
What is sampling error or sampling variability?
The variation amongst samples
Formula for standard deviation of sample proportion
square root of p x q / n
What is the independence assumption
the sampled values must be independent of each other. One success can not depend on the outcome of the subsequent trial.
What is the sample size assumption?
The sample size (n) must be large enough.
Randomization condition?
The subjects in the data needs to be completely randomized
What is the 10 percent condition?
if subjects in the sample you are using are not being replaced after chosen then the sample size should not be larger than 10 percent of population
Success and failure condition?
The number of successes and failures must be at least 10
What is margin of error?
The distance from the mean or number of standard errors (standard deviation) (Total distance)
WHat is critical value?
The number of standard errors we must stretch out on either side of the mean
What is the formula for margin of error?
critical value x standard error
