Question

You and your lab partner are asked to determine the density of an aluminum bar. The mass is known accurately (to four significant figures). You use a simple metric ruler to measure its dimensions and obtain the results for Method A. Your partner uses a precision micrometer and obtains the results for Method B.

Method A ()	Method B ()
2.1	2.700
2.2	2.698
2.6	2.702
2.3	5.805

The accepted density of aluminum is 2.702 .

Calculate the percent error for each method's average value (2.3 for Method A and 2.700 for Method B).

Calculate the standard deviation for each set of data. The average value for Method A is 2.3 and the average value for Method B is 2.700 .

Answer 1

N is no. Of measurement, Xi is particular measurement. (N+1) is degree of freedom.experiment value is lab value and accept value given in question.