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Fri 3 Sep, 2010 03:40 am
Alcohol and nicotine consumption during pregnancy may harm children. Because drinking and smoking behaviors may be related, it is important to understand the nature of this relationship when assessing the possible effects on children. One study classified 452 mothers according to their alcohol intake prior to pregnancy recognition and their nicotine intake during pregnancy. The data are summarized in the following table.
--------------------------------------… (milligrams/day)
Alcohol (ounces/day)------------ None----- 1–15 -----16 or more
None --------------------------------105 --------7 ------------11
0.01–0.10--------------------------- 58 --------5 ------------13
0.11–0.99--------------------------- 84--------37 -----------42
1.00 or more ---------------------- 57 -------16 -----------17
Q1) How many degrees of freedom are there in the Chi-Squared test?
Q2) What is the value of the test statistic?
df in a contingency table is defined as (#rows-1)(#columns-1). You have 4 rows and 3 columns so your #df is (4-1)(3-1) or 3 times 2 = 6
You want to do a Chi-Squared test for Independence and can use the process described here
Quote:Chi Square Test of Independence
For a contingency table that has r rows and c columns, the chi square test can be thought of as a test of independence. In a test of independence the null and alternative hypotheses are:
Ho: The two categorical variables are independent.
Ha: The two categorical variables are related.
At the bottom of the page...
If you don't have a computer program there's a link to a chi-square calculator at that site.
@abc123456789,
Darn it! I thought this thread was going to be about exponential chia pets populations!
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