SOLUTION: 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 stand

Click here to see ALL problems on Probability-and-statistics

Question 1195366: 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 is 2.60 cups per day for those drinking regular coffee and 2.76 cups per day for those drinking decaffeinated coffee. A random sample of 64 regular-coffee drinkers showed a mean of 4.42 cups per day. A sample of 54 decaffeinated-coffee drinkers showed a mean of 5.91 cups per day. Use the 0.010 significance level.
a. State the null and alternate hypotheses.
multiple choice 1
====(H0: μRegular ≥ μDecaf; H1: μRegular < μDecaf) correct

b. Compute the test statistic. (Negative values should be indicated by a minus sign. Round your answers to 2 decimal places.)

c. Compute the p-value.

d. What is your decision regarding the null hypothesis?
multiple choice 2
======(Reject H0) answer

e. Interpret the result.=The mean number of cups for regular coffee drinkers is less thanselected answer correct decaffeinated coffee drinker
Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website!
2 sample z-test
SE is sqrt (sigma 1^2/n1+sigma2^2.n2)=sqrt(2.6^2/64+2.76^2/54)=sqrt(0.2467)=0.50
z=diff in mean/SE
=-1.49/0.5
=-2.98 is the test stat
p-value=0.001
reject Ho at the 0.01 level.