# sb1 t3 7 8 9 • Name:

MonthBags
Jan13600
Feb12125
Mar18200
Apr13650
May13650
Jun13650
Jul14250
Aug14250
Sep15800
Oct10500
Nov19000
Dec24750

Part I: Chapter 7

The data is the number of bags of doughnuts produced per month by Namiki Bakery in 2010. Pretend that the data is normally distributed.

1. n _________ Determine the sample size n for the data.
2. x = _________ Determine the sample mean x for the data.
3. sx = _________ Determine the sample standard deviation sx for the data.
4. z = _________ Calculate the z-score for the number of bags of doughnuts produced in December.
5. ______________ Is the December production run usual or unusual?
6. p(bags ≤ 8815) = _________ Use the normal distribution function NORMDIST to calculate the population percent of months that produce 8815 or fewer bags of doughnuts.
7. p(bags ≥ 19271) = _________ Use the normal distribution function NORMDIST to calculate the population percent of months that produce 19271 or more bags of doughnuts.
8. p(8815 ≤ bags ≤ 19271) = _________ Use the normal distribution function NORMDIST to calculate the population percent of months that produce between 8815 and 19271 bags of doughnuts.
9. p(bags ≤ __________) = 0.20 Use the normal distribution inverse function NORMINV to calculate the number of bags BELOW which are found the 20% lowest production of doughnut bags.

Part II: Chapter 8
Use the sample size and standard deviation from part I. Presume that the data is normally distributed.
10. SE = _________ Calculate the standard error for the doughnut bags data.

Part III: Chapter 9
Use the data and results above in this section.
11. df = _________ Calculate the number of degrees of freedom..
12. tc = _________ Calculate tcritical using a 95% level of confidence.
13. E = _________ Calculate the margin of error for the mean E.
14. p(__________ ≤ μ ≤ __________) = 0.95 Calculate the 95% confidence interval for the mean.