Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A random sample of 12 observations is takenfrom a normal population having the v

ID: 2952274 • Letter: A

Question

A random sample of 12 observations is takenfrom a normal population having the variance 42.5. Find theapproximate probability of obtaining a sample standard deviationbetween 4.23 and 9.21. A random sample of 12 observations is takenfrom a normal population having the variance 42.5. Find theapproximate probability of obtaining a sample standard deviationbetween 4.23 and 9.21. A random sample of 12 observations is takenfrom a normal population having the variance 42.5. Find theapproximate probability of obtaining a sample standard deviationbetween 4.23 and 9.21.

Explanation / Answer

Since twelve observations are from a normal distribution with2=42.5 we know
X2=(n-1)s2/2 is distributed as a chi-square with n-1 degrees offreedom. Thus the probability of a sample standard deviationfalling between 4.23 and 9.21 is given by P{11(4.23)2/42.5<X2<11(9.21)2/42.5}=.923
Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote