Stat 301 – Week 6 Assignments

 

For Monday (10/27):

·         Submit “PP for Monday Oct 27” in Blackboard

·         You may also want to practice with 4.2.3, initially assigned for Friday and now available

 

For Tuesday (10/28):

·         Turn in Lab 3

·         Submit PP 4.3.2 in Blackboard. If you already submitted an answer, I believe you can edit it after Monday’s class.  If not, let me know and I can “reset” your submission.

o   Investigation 3.3.2 is on p. 219, you just need the first paragraph though it wouldn’t hurt to read the study conclusions either (p. 223)

·         Have started Investigation 4.3.3 (p. 311) parts (a)-(c)

 

For Thursday (10/30):

·         Fix the two typos in Investigation 4.3.5 noted on the errata web page

·         Submit solutions to the following in Blackboard: It has been conjectured that when asked whether they prefer to hear good or bad news first, people tend to choose bad news.  Suppose we have a simple random sample of 95 Cal Poly students and find that 83% want to hear bad news first. A test of significance can be performed to determine whether this is convincing evidence that a majority of all Cal Poly students have a genuine preference to hear bad news first yielding p-value » 0. The following are examples of errors in the analysis of this study.  In each case, explain what is wrong.

(a) Checking technical conditions with 95(.83) = 87.85 and 95(1-.83) = 16.15.

(b) Stating the hypotheses as H0 = .5 vs. Ha > .5

(c) Stating the hypotheses as H0: m = .5 vs. Ha: m > .5

(d) Stating the hypotheses as H0:  = .83 vs. Ha:  > .83

(e) The parameter is whether a student prefers to hear good or bad news first.

(f) The p-value reveals that the probability that H0 is true is essentially zero.

 

Due Friday (10/31):

·         Read the introductory paragraph for Investigation 3.3.5 (p. 229) and consider part (a). Note the awkwardness of computing a two-sided p-value as discussed on p. 231.

·         HW 5 (see below)

 

Note: Lab 4 will be due Tuesday 11/4. The assignment will be to complete Exploration 4.3 (p. 327), parts (d)-(r).  Remember to include screen captures of relevant applet output (e.g., screen captures using the Print Screen button on the keyboard).


HW 5  - Due Friday 10/31

Reminders: Feel free to use the normal probability calculator applet instead of Minitab for the calculations (and include screen captures of the output).  Remember to include all relevant output.  Show your work, label your axes, etc.

 

1) Investigation 4.1.2 (p. 285)

Include all of your graphs (you can resize to allow many to fit on one page)

 

2) Exercises #21 and #22(a)-(e) (p. 389-390)

 

3) Recall the popcorn workers study from Investigation 1-1.  Another issue is how these workers compared to the general population. Information about the general population was obtained from the National Health and Nutrition Examination Survey (NHANES III).  The NHANES study found 5.5% as the baseline rate of airway obstruction in the general population.  At the popcorn-plant, they observed 21 of 116 workers with airway obstruction.  Of interest is whether the rate of airway obstruction is higher among the population of popcorn workers compared to the national results.

Consider the population of all microwave popcorn workers.  Let p represent the proportion of this population with airway obstruction.  Suppose we consider the sample at this plant to be representative of all popcorn workers. Carry out a test of significance to determine whether there is evidence that the airway obstruction rate in the population of popcorn workers is higher than national rate.  [State your hypotheses (in symbols and in words), discuss whether you can Central Limit Theorem in this study (but do so either way for practice), report the test statistic value and the (approximate) p-value, and state your conclusion in context.]

 

4) Exercise #24 (p. 390)

To use Minitab to graph a function, you need to enter some x values into a column, e.g.,

            MTB> set c1

     DATA> 0:1/.01      range is 0 to 1 in increments of .01

            DATA> end

Then calculate the f(x) values, e.g.,

            MTB> let c2= sqrt(c1*(1-c1)/100)

     MTB> plot c2*c1;        this plots f(x) vs. (x)

            SUBC> connect.                 Connects the dots

 

5) Exercise #34 (p. 393)

We will cover the relevant material on Thursday. In (c), you will verify that the Wald procedure is valid and so use it in (d).  Remember to interpret your interval.

 

 

Advance warning: I believe these following exercises will be on HW 6

 

Exercise #25 (p. 390)

 

Exercise #30 (p. 390-392)