4. A new procedure for the determination of sulfur in coal was tested on a standard coal sample with a certified value of 2.14% sulfur by mass. The new procedure gave results of 2.11%.2.07%.2.04%. 2.06% and 2.16% for five separate determinations. a) Does the new procedure give the correct result at the 95% confidence level? b) Does the new procedure give the correct result at the 90% confidence level? c) Based on your answers to parts (a) and (b), fill in the blank in the following statement: There is at least a _ \% chance that the difference between the certified value and the values obtained by the new procedure is due to random error