Reference no: EM1311602
Question 1: In 2001, the U.S. Department of Labor reported the average hourly earnings for U.S. production workers to be $14.32 per hour (The World Almanac 2003). A sample of 60 production workers during 2003 showed a sample mean of $14.68 per hour. Assuming the population standard deviation σ = $1.55, can we conclude that an increase occurred in the mean hourly earnings since 2001? Use α = .05.
a. State the hypotheses.
H0: α =
Ha: α >
b. What is the p-value (to 4 decimals)?
Question 2: 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 Investor Optimism Survey, conducted over the period January 2 to January 15, found that 67% of investors were confident of meeting their investment objectives (CNBC, January 20, 2006).
a. Formulate the hypotheses that can be used to test the validity of the brokerage firm executive's claim.
H0: p ≥
Ha: p <
b. Assume the UBS Investor Optimism Survey collected information from 300 investors. What is the p-value for the hypothesis test (to 4 decimals)?
c. At α = .05, should the executive's claim be rejected?