An investigator wants to estimate caffeine consumption in high school students.  How many students would be required to estimate the proportion of students who consume coffee?  Suppose we want the estimate to be within 5% of the true proportion with 95% confidence.            Alpha = ________                  Z= ________                   p= ________                 E = ________                   n= ________

Pi- P2 Z. = %3D SE Suppose a drug company is developing a vaccine, designed to protect against a particular virus. The company states that the vaccine will be equally effective for men and women. In its initial stage, a researcher selects a random sample of 200 men and 100 women independently. At the end of the study, 15 of the men and 10 of the women showed symptoms of the virus after taking the vaccine. Is there enough evidence to conclude that there is a significant difference in the proportions of men and women who show symptoms of the virus after taking the vaccine? (a) State the appropriate hypotheses to answer this question. (b) Compute the test-statistic. (c) (i) Calculate the p-value. (ii) Interpret the p-value you have found. (d) State your conclusion in context of the situation. Page 1 135

Questions #5 and #6

Scenario: 200 people were asked, “Who is your favorite superhero?” Below are the data.  Test the null hypothesis that the population frequencies for each category are equal.  α= .05. Iron Man Black Panther Wonder Woman Spiderman fo = 40 fo = 60 fo =55 fo = 45 fe = fe = fe = fe =   Chi Square test statistic = ______ Group of answer choices

ch.8 question 11 sample You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately 64%. You would like to be 98% confident that your estimate is within 4% of the true population proportion. How large of a sample size is required? Do not round mid-calculation.n =