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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: lonelinesspains on September 23, 2020, 06:08:53 AM

Hi dear friends,
please help me with answering this Problem:
We used two methods to determine nitrate concentration in water, 3 repetition of measurements have been done in each method. Do the means in two methods differ significantly?
method A: 10, 10, 11 ppm
method B: 11, 11, 10 ppm
Degree of freedom (95%): 1 2 3 4 5 6
t: 12.7 4.30 3.18 2.78 2.57 2.45
Reference: Statistical Data Treatment and Evaluation, SKOOG

The rules of the forum require you to show your attempts at solving the problem, before we can provide any help.
Regards,
Motoball

Dear my friend,
I've tried to solve this problem before but already failed.
please give me the answer or at least some instructions to find solution.
thanks

If you show what sort of understanding you have
From your class or textbook about statistics and what do you know about Degrees of freedom
Someone knowing your level of understanding may be able to give you hints
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hint from the internet
The degrees of freedom in a statistical calculation represent how many values involved in a calculation have the freedom to vary. The degrees of freedom can be calculated to help ensure the statistical validity of chisquare tests, ttests and even the more advanced ftests.