Question

2. The consumer magazine also claims that the cinnamon rolls at STARBUCKS do not equal 8 ounces.    A random sample of 25 customers purchasing cinnamon rolls yields the following results:

• the sample mean equals 8.15 ounces
• it is known from previous studies that the population standard deviation equals 0.25 ounces.

a. What formula would you use to set up a 95% confidence interval for the true mean?

b.   What z-value would you use to set up a 95% confidence interval for the true mean?

c. What formula would you use to see what sample size is required if you want to be 90% sure that the sample mean will be within 0.2 ounces of the true mean?

d. What z value would you use to see what sample size is required if you want to be 90% sure that the sample mean will be within 0.2 ounces of the true mean?

e.   Test the hypothesis that the true population mean is not equal to 12 ounces.  Set the type one error equal to 1%. What test statistic would you use?  

f. What is the null hypothesis? Ho: μ  12

g. What is the critical Z value for deciding whether to Reject of Not Reject HO?| Z* |=

h. Calculate the Z-stat =

i. Decision: Reject or DNR Ho. Ho.

Answer 1

answered by: anonymous