Question

F-Test and corresponding t-Test for 95% confidence Three different methods were used to deterrmine the concentration of a certain bulk solution af acetic acid. The three methods were all titrations, using the same standard NaOH solution as titrant, and identical volumetric technique. The only difference was the choice of acid-base colour indicator to reveal the endpoint. For each method, the average acetic acid concentration and its standard deviation for the number of titrations (n) performed are summarized below IndicatorCH,COH+S (M) n 1) m-nitrophenol 2) o-cresolphthalein ll 3) phenolphthalein 0.74730 ± 0.00690 0.76150 ± 0.00322 0.76318 ± 0.003 17 6 11 6 Compare methods 1&2 using the F test at the 95% confidence level. cakulsted4.59 You are correct. Your receipt no, 1s 154-4304Erev s Fabie Submit Answer Incorrect. Tries 1/4 Previous Tries Based upon the above F-values, decide upon the appropriate t test and report the corresponding calculated and table values tcaoute Sutbmit Answer Incorrect. Tries 1/4 Prexvious Tries tool じSubmit Answer Tries 0/4 95% confidence level Submit Answer Is there a difference resulting from the use of indicators 1 & 2 at the 95% confidence level? Yes O No Submit Answer Tries 0/1

Answer 1