It has been suggested that no more than a quarter of Americans who invest in stocks have even a basic knowledge of investing. To investigate, Money Magazine and the Vanguard Group conducted a study in which 1555 investors were selected from across the United States and given a simple quiz on investing (source: ifa.com). If 423 of the investors who took the quiz received a passing score, would this be sufficient sample evidence to reject a null hypothesis that no more than 25% of the population of all investors would receive a passing score on the quiz? Use a significance level of 5%.
a. Show the null and alternative hypotheses.
b. Based on the sample result, should you reject the null hypothesis? Explain.