An SRS of 20 orangutans is selected, and 65 cc of blood is to be drawn from each orangutan using a 100 cc syringe. In the sample, the mean volume is 64 cc and the standard deviation is 12 cc. Assume that in the population of all such procedures, the amount of blood drawn follows a Normal distribution with mean μ.

We are interested in a 95% confidence interval for the population mean volume. The margin of error associated with the confidence interval is
A. 2.68.
B. 4.64.
C. 5.62.
D. 6.84.

Question

An SRS of 20 orangutans is selected, and 65 cc of blood is to be drawn from each orangutan using a 100 cc syringe. In the sample, the mean volume is 64 cc and the standard deviation is 12 cc. Assume that in the population of all such procedures, the amount of blood drawn follows a Normal distribution with mean μ.

We are interested in a 95% confidence interval for the population mean volume. The margin of error associated with the confidence interval is
A.	2.68.
B.	4.64.
C.	5.62.
D.	6.84.

valpey · Answer

95% CI corresponds to plus or minus 1.96 Standard Deviations. If the Standard Deviation of a single draw is 12ccs, then the Standard Deviation of n draws is 12/sqrt(n). So yeah, I get plus or minus 5.26. Maybe C is a typo where they transposed the 2 and the 6?

anonymous · Answer

yes, i got 5.25

anonymous · Answer

im guessing that c is the closest answer

anonymous · Answer

i have another question. ill resubmit the post