Contingency Table Interpretation

Mogarrr
Messages
120
Reaction score
6

Homework Statement


10.24 Is there any relationship between the type of treatment and the response? What form does the relationship take?

Here's that data (column variables are responses):
<br /> \newcommand\T{\Rule{0pt}{1em}{.3em}}<br /> \begin{array}{|c|c|c|c|c|}<br /> \hline Treatment &amp; +Smear &amp; +Smear,-Culture &amp; -Smear,-Culture &amp; Total\T \\\hline<br /> Peniclillin \T &amp; 40 &amp; 30 &amp; 130 &amp; 200 \\\hline<br /> Spectinomycin(low dose)\T &amp; 10 &amp; 20 &amp; 70 &amp; 100 \\\hline<br /> Spectinomycin(high dose)\T &amp; 15 &amp; 40 &amp; 45 &amp; 100 \\\hline<br /> Total\T &amp; 65 &amp; 90 &amp; 245 &amp; 400 \\\hline<br /> \end{array}<br />

Homework Equations

The Attempt at a Solution


I've already done a chi-square test and found what was hinted in the question, the treatment and response are not independent.

What's a good way to describe the relationship?

I've thought of combining 2 treatment so that I could do Cochran Armitage Trend Test, but given the treatments, I see no clear way of combining categories.

I'm also thinking of commenting on the conditional probabilities and how they differ from the marginal probabilities. (I think the probabilities in the cells can be thought of as conditional probabilities). For example: the probability of a negative smear, negative culture given the treatment was a high dose of spectinomycin is \frac {45}{100} compared to the probability of a negative smear, negative culture, which is \frac {245}{400}.
 
Physics news on Phys.org
Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

Similar threads

Replies
3
Views
2K
Back
Top