Stat211 f04 midterm2 - "fl STAT Z Midterm 2 a 1.“...

Info icon This preview shows pages 1–2. Sign up to view the full content.

Image of page 1

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

Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: "fl \, STAT Z Midterm 2 ' a 1.“ You must use a Blue Book for this exam. It is OK to write on your exam paper, but make sure everything that you want me to see when I grade your exam is in the blue book. Show all work where appropriate. This exam has four problems followed by 10 True/False questions. There are 60 points possible, and the true/false questions are worth a total of 20 points, so make sure to leave enough time to do them. There are 60points possible on this exam. When you are finished, place this exam inside your blue book and turn it in with your blue book. There is a copy of the Normal Distribution table at the end of this exam. The data for problems 2 and 4 can be found in the MINITAB file called EXAM2 in the data folder of the Peck folder on your desktop. 1. Suppose that the weights of bags of plain M&M's form an approximately normal distribution with a mean of 1.9 oz. and a standard deviation of .1 oz. m; l D’ ': ' l (4) . A bag is under-filled if it weighs less than .84 oz. Approximately what . a propan of bags are under-filled? ' . 84’ l .Ql \ V__ A ‘ \ a (4) b. The lightest 10% of all bags of plain &M's weight less than what amount? 2. A maker of chocolate chip cookies claims an average of 30 chips per cookie. To test this claim, 18 cookies are selected at random and the number of chips in each of the selected cookies was recorded. The resulting data can be found in the column labeled CHIPS in the EXAM2 data file. (2) a. Are there any outliers in this data set? (Use MINITAB to construct a boxplot. You DO NOT need to copy the boxplot onto your test paper or print it out--just use it to determine if there are outliers).) (4) b. Based on looking at the boxplot of the data, is it reasonable to assume that the population distribution of the variable x = number of chips is approximately normal? Briefly explain why or why not. (6) c. Is there sufficient evidence to conclude that the mean number of chips per cookie is less than the manufacturer's claim of 30? Test the appropriate hypotheses using a = .05. ' 4;). low §%; ¥ 4. The 2 distribution for random samples of size 4 from a population with mean 40 STAT a Midterm 2 m 40 0?? The 5 distribution for random samples of size 4 from a population with mean 40 and standard deviation 8 will have a standard deviation of 4. and standard deviation 8 must be approximately normal. 5. The sample mean, 35 , will be within 2:7: of the true population mean for about n 95% of all possible random samples. 6. If a 95% confidence interval for a population mean is reported to be (38, 47), this means that the probability that u is between 38 and 47 is .95. 7. If a 99% confidence interval and a 90% confidence interval are both constructed using the same set of data, the 99% confidence interval will be wider. 8. Suppose that 15% of all those receiving a particular treatment improve after treatment. Since each patient who receives the treatment either improves or does not, a reasonable way of simulating an experiment where 3 patients are treated would be to use three random digits with the odd numbers representing improvement and the even numbers representing no improvement. 9. In a hypothesis test, decreasing the probability of type I error increases the probability of type 11 error. 10. An investigator collects data to determine if there is reason to believe that the mean length of time required to solve a geometric puzzle is greater than 3 minutes. The appropriate hypotheses would be H 0 : [,1 > 3 vs. H a : ,u < 3. ...
View Full Document

  • Fall '04
  • staff

{[ 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