STAT 200: Elementary Statistics

Here is the key.  Email or visit my office if you have questions.

regression_hw_key.pdf

Office hours for finals week:

Monday: 10-Noon
Tuesday: 10-Noon
Wednesday: 10-Noon
Friday: 10-Noon

Or by appointment

The final (150 points) will take place Wednesday, April 5th at 2:00.  The location is 101C Junker Center.

There will be a review on Tuesday, May 4th at 8:00 PM in 165 Nick.
Chapter 2 (Page 117)
13, 21-24, 25, 29, 37-40

Chapter 5 (Page 297)
23, 24, 33-36, 39-45 odd

Chapter 6 (page 353)

1 (mean=103.5, sd = 34.7), 3, 5, 17, 19, 21, 31, 33, 39

Chapter 7 (page 427)

7, 9, 19, 22, 20, 21, 45

Chapter 8 (page 481)

7 and 8

Chapter 9

final_review.pdf

final_review_answers.pdf

This homework assignment is based on correlation and regression.  The homework assignment can be downloaded below.  Questions are due Friday, April 30th.  The graded assignments will be available Monday of finals week at my office (Benson 87).

regression_hw.pdf

This homework assignment is based on Analysis of Variance (ANOVA).  The homework assignment can be downloaded below.  Questions 2-4 and 6 are due Friday, April 23rd.  The answers to 1 and 5 are given below.

anova_homework.pdf

Question 1

Ho: mu1=mu2=mu3
Ha: At least one pair not different.

There is not enough evidence (F= 2.14,p=0.156) to suggest a difference among the average prices of the battery types.


               df                   ss                  ms             F
Size       2                 513.42            256.71       2.14    
Error    13                1554.33           119.56
Total    15                2067.75

Question 5

Different: Blue-Green,Blue-Yellow, Green-White, Green-Yellow, White-Yellow
Same: Blue-White

Here is the line plot:

Yellow   47.2
Green   31.2
White  16.2   |
Blue    14.8   |

This assignment is due Friday, April 16th
Hand-in EVEN questions only

Section 8.1, Page 445
19-24

Note:  Use the p-value approach described in class, not the critical value approach described in the paragraph on page 445.  Be sure to write your conclusion in the context of the problem.

Here are the two files for the lab.

nitd.mtw

Hand in the EVEN problems from the book and problems 2 and 3 (yes 3) from the handout.

Section 7.2 (page 389)

37 (mean=14.9, standard deviation = 4.3), 39, 40

Section 7.4 (page 411)

Conduct these tests like I described using a p-value (not the critical region like suggested in the book).

9,10,11, and 12

And questions 2 and 3 from this handout:

ztest_ci_worksheet.pdf

Section 1:

9:30-11:30 in Nick 170

Section 2

12:00-2:00 in Nick 168

Answers will be added soon

Chapter 5 (page 297)

39-45 odd

Chapter 6 (page 353)

1 (mean=103.5, sd = 34.7), 3, 5, 17, 19, 21, 31, 33, 39

Chapter 7

7, 9, 19, 22

Two sample proportion problem:

Among children under the age of 7, 134 out of 548 tested positive for the H1N1 virus in a large school district. For children between the ages of 7 and 12, 28.4% out of 750 tested positive for H1N1. Construct the 95% confidence interval for the difference in percent infections between children under the age of 7 and 7 or older.

Two sample mean problem:

Two groups of laboratory rats are raised in different size cages. Group A rats were raised in cages four times as large as the rats in Group B. Based on the data below, use a 90% to determine if there is a difference in the body weights. Be sure to interpret your confidence interval in the context of the problem.

                               Group A Group B

Mean                       418g      392g

Standard Deviation    35g       42g

Sample Size             43         38

ANSWERS

22.

Ho: mu <= 650

Ha: mu > 650

z* = 1.17

p = .121

Fail to reject, there is not enough evidence to suggest that the daily cost is more than $650.  We cannot reject the claim.

2 Sample Proportion CI

-.039 +/- .049 = (-.088,.010)

2 Sample Mean CI

26 +/- 14.23 = (11.8,40.2)