N100 x bar170000 sd10000 95 ci is 168040 171960 ans

Info icon This preview shows pages 3–4. Sign up to view the full content.

View Full Document Right Arrow Icon
n=100 x-bar=170,000$ sd=10,000$ 95% CI is (168040, 171960) $ ANS_________________ 15. Suppose a newspaper article reports that the average house price in Columbus OH is $180,000. Do you agree with their report, based on your data from #37? EXPLAIN BRIEFLY. It is outside of 95% CI so it is very unlikely. 3
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
YES NO #16-18: Suppose it is known that 30% of students at a particular college are smokers. 16. A sample of 5 students from that college is selected at random. Find the probability that the number of smokers in this sample is less than 4. P=0.3 n=5 k=0,1,2,3 P(x<4)=1-P(X=4)-P(X=5)=1-0.0308=0.9692 ANS _______________ 17. A sample of 100 students from the college is selected at random. Find the probability that the number of smokers in this sample is less than 40. np=30 n(1-p)=70 both are bigger than 10 so you can use normal approximation mean=30 std=4.58 P(X<40)=P(Z<2.18)=0.9854 18. There are 2 conditions that need to be met in order to be able to use the normal approximation. What is the minimum sample size needed in order to meet these two conditions in this particular situation (the smokers problem above)? 34 when n=34 np>10 n(1-p)>10 but n=33 doesn’t satisfy the first condition #19-20: Suppose the time to delivery of a package has a normal distribution with mean 2 days and standard deviation 0 .5 days. 19. What is the chance that one package selected at random took more than 2.2 days to deliver? P(X>2.2)=P(Z>(2.2-2)/0.5)=1-0.6554=0.3446 ANS___________ 20. What is the chance that 36 packages selected at random have an average delivery time of more than 2.2 days? P(X-bar>2.2)=P(Z>(2.2-2)/(0.5/6))=1-0.9918=0.0082 ANS____________ 4
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern