[13] 1. Analyse the following data appropriately. State any assumptions you make and do what you can, including descriptive statistics and graphical methods, to check the validity of the assumptions.
The molar percentage of bile salts was determined for a sample of 6 children suffering from cystic fibrosis who were receiving a pancreatic enzyme treatment, and for a second sample of 9 who had ceased taking the treatment for one week.
|
Subject: |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
|
Treated: |
54.8 |
70.8 |
54.3 |
64.5 |
50.5 |
73.3 |
|
|
|
|
Untreated: |
61.5 |
54.8 |
62.4 |
74.3 |
80.3 |
77.7 |
78.2 |
74.0 |
48.3 |
[5] 2. Suppose that you want to repeat the study of Q1 but with enough subjects that a two-sided 5% test has a 90% chance of detecting a difference in molar percentage of bile salts if it is 5 or greater. How many subjects should you have in each group?
[5] 3. In Assignment 1, you looked at data from 123445 pairs of consecutive offspring and classified them by the sex of the first and second child. Compute a 99% confidence interval for the odds ratio. What can you conclude?
|
|
|
First Child: |
|
|
|
|
F |
M |
|
Second Child: |
F |
30575 |
30244 |
|
|
M |
30653 |
31973 |
[7] 4. Ten independent measurements of the length of a rectangle had a mean of 9.6 m and coefficient of variation equal to 0.06. Ten independent measurements of the width had a mean of 3.4 m and coefficient of variation 0.09. Find an approximate 95% confidence interval for the length of the diagonal.