Albyn Jones Math 141 Use the following decision rule. This is a parameter estimation, which is an inference of a sample based on a population of data. It can be used when n ≥ 30, or when the population is normally distributed and σ is known. Z-Test: A Z test is a statistical hypothesis test which is best used when the population is normally distributed with known variance and population size greater than 30. The one-sample z-test is used to test whether the mean of a population is greater than, less than, or not equal to a specific value. Write a statement to … The primary reason to use the Z-test for a sample proportion is ease of computation, you can often do the arithmetic mentally, or on any calculator. The z-test assumes that the population standard deviation is known. In R, binom.test or prop.test are better options! Thus for binomial population, the hypothesis we want to test is whether the sample proportion is representative of the Population proportion P = P 0 against H 1: P≠P 0 or H 1: P>P 0 or H 1: P