Module 12 Assignment
One Sample z-test [Refer to the Module 12b Slides lecture for a practice example]
We take a random sample of 430 voters in Washington County and ask if will vote for candidate x (We'll call her Ms. Peanut). Out of the 430 respondents, 246 say they plan to vote for Ms. Peanut and the rest say they will not. Do we have enough evidence to say that Ms. Peanut has more than 50% of the population of Washington County planning to vote for her (at alpha=.05)?
a) Set up the null and alternative (one-sided) hypothesis for a one-sample z-test for this problem.
b) Use the formula below to calculate the z-statistic. Remember that p-hat is the proportion from your sample and p0 is the proportion representing the null hypothesis, .50 (or 50% as a percentage).
Show your work or describe the process for calculating the z-statistic.
c) What is the one-tailed critical value for a one-sided z-test? (see table below). Compare this value to the z-statistic from part b. Can we reject the null at alpha=.05? How do you know?
