Hypothesis test for single proportion.
Speaking to a group of analysts in January 2006, a brokerage firm executive claimed that at least 70% of investors are currently confident of meeting their investment objectives. A UBS Investors Optimism Survey, conducted over the period January 2 to January 15, found that 67 percent of investigators were confident of meeting their investments objectives (CNBC, January 20, 2006)
a)Formulated the hypotheses that can be used to test validity of the brokerage firm executive claim.
b) Suppose UBS Investor Optimism Survey collected information from 300 investors. What are the p-values for the hypothesis test?
c) At α = .05 should the executive's claim be rejected?