Question

You are using two different analytical methods to do elemental analysis (analyzing the elemental composition) of a sample. When using combustion analysis coupled with gas chromatography and thermal conductivity detection (Method 1), you find that the sample has 64.42 %C, 6.39 %H, and 3.15 %N (w/w). When using combustion analysis coupled with infrared spectroscopy (Method 2), you find that the sample has 64.97 %C, 6.00 %H, and 3.33 %N (w/w). [What type of t test should you use to compare these methods? What is the null hypothesis in this case?] What is t_calc?  What is t_table?   Do the two methods give the same answer “within experimental error” (answer either yes or no)?

Answer 1

Paired t - test fir difference of means is used to compare two methods.

Null Hypothesis - There is no significant difference between the combustion analysis coupled with gas chromatography and thermal conductivity detection by Method 1 and Method 2 .

t cal= 0.004

t tab = 2.132

Yes, the two methods gives the same answer as null hypothesis is accepted according to t test.