Homework SourseThe third shift at the Microsofts Windows security unit in R
The third shift at the Microsoft\'s Windows security unit in Redmond, Washington is considering replacing its coffee brewing units with new German-made brewers. As the newest member of this elite Microsoft team, you have been assigned to investigate this proposal. Develop a 99 percent confidence interval for the average yield (cups per pound) for the new German coffee brewer. The margin of error should be no bigger than 0.3 (three tenths of a cup). Based on experience with the current coffee makers, your best guess for the population standard deviation, sigma, is 1.2 cups. How big of a sample do you need? Calculate the estimated sample size needed for the above scenario and communicate your findings to the business manager. please show for me to plug in for excel statistics.
| Inputs: | ||||||
| Planning Value for P-Star: | <— Input the appropriate number for your situation. | |||||
| Desired Margin of Error: | <— Input the appropriate number for your situation. | |||||
| Confidence Level: | <— Input the appropriate number for your situation. | |||||
| Intermediate Calculations: | ||||||
| Z-Multiple: | ||||||
| Sigma: | ||||||
| M.E. Squared: | ||||||
| Z-Multiple Squared: | ||||||
| Results: | ||||||
| Sample Size Needed: | (rounded up to a whole number). |
Solution
let the sample size needed is n
margin of error is given as sigma/sqrt(n)*tao0.005 0.005=alpha/2 since here alpha=0.01
where sigma=1.2 tao0.005 is the upper 0.005 point of a N(0,1) distribution.
so tao0.005=2.57583
now 1.2/sqrt(n)*2.57583<=0.3
or,sqrt(n)>=10.30332 or n>=106.158403 =107 [answer]
