Statistical Sciences 2035 Study Guide - Standard Deviation, Categorical Variable, Sampling Distribution
Document Summary
Select a random sample of size n from a population and record the count, x, of. We are interested in estimating p, as it is often unknown. To do this, we use our sample and calculate the sample proportion of success p = x n. Since p is calculated from our sample data, it is a statistic: since it is a statistic, it has a sampling distribution associated with it. If you took the 10,000 values of p , added them up and divided by 10,000 you would get p. In other words, p = p: spread. If you took the 10,000 values of p and calculated the standard deviation, you would get: p. Approximately normal if n is large : to see if this normal assumption is valid, you must check: np 5 and n(1 p) 5. This means that we can use the following transformation and the z-table (a. 4) to solve problems: p p.