STAT 20 Study Guide - Quiz Guide: Simple Random Sample, Shobana, Null Hypothesis

• School: Berkeley
• Department: Statistics
• Course: STAT 20
• Professor: All

Document Summary

Sign the exam in the indicated space to con rm i swear i did not cheat on this quiz, nor did i help anyone else to cheat. For your convenience, here are some quantiles of the standard normal curve: 1. 65: a california city has 35,000 inhabitants, of whom some large fraction are registered democrats. The mayor of the city decides to do a survey, and asks his assistant to take a simple random sample of 900 people from the city and the sample has 650 democrats. Now the client would like them to reduce the margin of error by 50% (that is, the new margin of error should be half the original margin of error), while keeping the same level of con dence. To do this, how many people should they now survey? (2 points: the p-value of a statistical test turns out to be about 0. 5%.