Please, help me on this question, guys! 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.
Let x be a random variable representing the price of a Congo-imported black diamond. Let the higher price be p. Then, P(x < p) = P(x < (p - mean)/sd) = P(x < (p - 60,430)/21,958.08) = P(z < 2) Therefore, (p - 60,430)/21,958.08 = 2 p - 60,430 = 2 x 21,958.08 = 43,916.16 p = 34,916.16 + 60,430 = 104.346.16
I think you just add all the sides even the ones you don't see. The left side of the shape is 6m as well as the right. and the same with the 4s. The answer is 36.
