In an experiment like you are going to do in Investigation 1 of lab this week, you count the number of beta rays from a 137Cs source. You do this 20 times during the same period of time and find the following number of counts: 969, 1012, 1025, 1082, 1023, 1003, 976, 1003, 1028, 972, 1000, 999, 993, 971, 1062, 1040, 1028, 951, 937, and 1017.
a) What is the average number of counts?
b) What is the (sample) standard deviation of your sample?
c) What percentage of your sample of numbers should be within < N > plusminus.gif2sqrt.gif< N > ?