Question

A coffee manufacturer is interested in whether the mean daily consumption of regular-coffee drinkers is less than that of decaffeinated-coffee drinkers. Assume the population standard deviation for those drinking regular coffee is 1.35 cups per day and 1.49 cups per day for those drinking decaffeinated coffee. A random sample of 49 regular-coffee drinkers showed a mean of 4.20 cups per day. A sample of 45 decaffeinated-coffee drinkers showed a mean of 5.10 cups per day.

Use the 0.050 significance level.

a-) Is this a one-tailed or a two-tailed test?

• One-tailed test.

• Two-tailed test.

2. State the decision rule. (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.)

The decision rule is to reject Ho. μRegular ≥ μDecaf if z < ___________

c- Compute the value of the test statistic. (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.)

Value of the test statistic _____________

d- What is the p-value?

The p-value is ___________

e- What is your decision regarding H₀?

• ( ) Reject H₀.

• ( ) Do not reject H₀.

Answer 1