3. A sample of 25 measurements is:

7

5

6

9

6

10

11

7

8

7

9

7

11

7

9

9

10

12

8

10

7

10

7

8

6

a. Compute , 2 and for this sample.

Answer: ________________ 2 _______________ __________________

Count the number of observations in the intervals , 2, 3 . Express each count as a percentage of the total number of measurements.

Compare the percentages found in part b to the percentages given by the Empirical Rule and Chebyshev's Rule.

d. Calculate the range and use it to obtain a rough approximation for . Does the result compare favorably with the actual value for found in part a.