Question

A simulation predicts the price per barrel of oil worldwide for end of 2019 based on certain macroeconomic parameters that they have variability. 5 replications of 1 year each were made and the price at Final in each of the 5 replicas was: 25.50, 32.75, 20.80, 38.20 and 27.50 dollars per barrel. Assume normality in this variable for the following: a) Determine the accuracy achieved with this number of replicates and with a 95% acceptance level. b) Calculate the number of replicas that must be made to achieve a accuracy of ± 0.35 with an acceptance level of 90%..

Answer 1

sample mean         x=	28.950
sample size             n=	5
sample std deviation s=	6.716
std error sx=s/√n=	3.0036

for 95% CI; and 4 df, critical t=		2.776
margin of error (Accuracy) E=t*std error                            =		8.338

b)

	for90% CI crtiical Z          =	1.645
	standard deviation σ=	6.716
	margin of error E =	0.35
required sample size n=(zσ/E)2 =(6.716*1.645/0.35)^2=          =		997(rounding up)