Question

URGENT HELP!

I know the answer for (a) so I'll write down, too. For (b) I tried "$89,000 because that is the price with the biggest unusual z-score" but I got that this part is incorrect because I needed to use the mean and standard deviation that I calculated along with z=2 to determine the threshold higher price. That got me lost.

Question: Consider the following prices for a sample of 10 Congo-imported black diamonds: $34,550; $45,500; $75,000; $33,000; $89,000; $40,000; $55,000, $62,500; $88,000; $81,750.

(a) Calculate mean and standard deviation for the above list of prices. Answer: Mean is 60,430 and Std Dev is 21,958.0813.

(b) What is the higher price you will pay for a Congo-imported diamond based on the sample from above? Explain your rationale for that.

Answer 1

For part b) you are saying that the highest price is 2 std dev from the mean?

Answer 2

in that case the highest price = mean + 2*std dev

fyi, the "z" value represents how many std dev from the mean

Answer 3

I don't know the answer for b! That is what i am trying to find out. When I tried "$89,000 because that is the price with the biggest unusual z-score" my teacher said that I needed to use the mean and standard deviation that I calculated along with z=2 to determine the threshold higher price. I don't know how to do this.

Could you get it?! I know (a) but don't know (b).

Answer 4

@mathmale @zepdrix
I have to run...

Answer 5

still need the help?

Answer 6

if you can give me a rationale explanation for the answer and check out the result for me I'd be glad