Homework


Every homework assignment should have, on the first page,

And you must staple your assignment.  Staplers will not be provided, so, if you haven't done so already, now is the time to invest in a stapler.  Loose pages might become separated and we are not responsible if your assignment receives a low grade because pages were missing.

DATASETS for homework are available in this directory.

Homework 10 , Due Friday, June 7
Homework 9, Due Friday, May 31 ALONG WITH HW 8.
Solutions to Homework 9


Homework 8 , Due Friday, May31.  Note Change of due date.

Homework 7 , Due Friday, May 17.

Homework 6 , Due Friday, May 10.


Homework 5, Due Friday, May 3.  This is the same day as the midterm!

Homework 4, Due Friday, April 26





Homework 3, Due Friday, April 19

HW 1, Due April 12

Read Chapter 2

One page 74, do problems 5,12,13,29 (what does R do?)
Hint:  See the pdf handout on how to load data into R and do basic manipulations.
HW2, Due April 12

For  problems 1-7, refer to the "risk" data set:

1) The distribution of “appliances” is “skewed right” .  This means that it has a “tail” that points towards the right.  This is common when the possible values are bounded below (by 0 here) and the typical score is a low one.
    a) Are there any variables you would expect to be right-skewed?  Symmetric?  Try it and see.

2) Uses graphically techniques, which, if any, would you say is the most risky, and why?

3)  What would you say is  a “typical” risk level for
    a) appliances
    b) nuclear
    c) pool

4) Which activities, if any, do you think show the most disagreemet in the risk ratings?  Why do you say this?

5) Without looking, which activities do you think will differ most by gender.  Check your hunches.

6) Without computing them, which will be greater: the median risk rating for swimming in a pool, or the average risk rating?  Explain.  Check your answer.  Give the mean and median.

7) Which of these activities would you say is rated as the riskiest?  Why?

8) For which of these situations is the empirical rule most likely to apply?  Explain.
a) 100 students take a midterm. The average score is 90 with standard deviation of 10.
b) 100 students take a midterm with average score of 50 and SD 10.

9) 200 students took a midterm. The average score was 60 and the SD was 5.  Approximately how many people scored above 50?

.10) Chapter 2: 19,22,32
11) Chapter 3: 4,9, 11, 18, 23, 24