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Analysis of variance
Message posted by Ebrahim Ali (via 139.230.127.6) on October 4, 2001 at 12:02 AM (ET)
Hi,
I was wondering if you cpild help me with this question:
Question:
samples of fish were taken from each of 5 rivers and analysed for PCB concentration:
River
1 2 3 4 5
2 4 12 7 13
3 6 9 5 9
6 8 10 6 15
5 5 8 9 10
3 7 9 5 11
7 7
Construct an analysis of variance and decide at 5% level of significance if there is sufficient evidence to indicate differences in PCB concentration.
Thank you in advance
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Re: Analysis of variance
Message posted by nancy diehl (via 129.176.151.122) on October 4, 2001 at 10:31 AM (ET)
The mathematics are long and tedious to write out in an e-mail, but you should be able to do this easily if you have access to EXCEL. First of all, you need to attach the Statistical Toolpack if it's not already attached to your EXCEL program. Select from the main menu bar TOOLS >> ADD INS >> STATISTICAL TOOLPACK. Once this is done, go back to the TOOLS selection and at the bottom you should see the option DATA ANALYSIS; select this. A window will pop up and you will want to select ANOVA: Single Factor. To set your data up in EXCEL, use a column for each River Sample and put the results below the river it goes to. When you go into the ANOVA part of the analysis, make sure you select that the data is grouped in columns and whether the first row has labels for the factors (River 1 to River 5). If you have done this correctly, you should find a calculated F-value of 11.46.
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