Kevlar epoxy is a material used on the NASA space shuttles. Strands of this epoxy were tested at the 90% breaking strength. The following data represent time to failure (in hours) for a random sample of 50 epoxy strands. Let x be a random variable representing time to failure (in hours) at 90% breaking strength.

0.52 1.80 1.52 2.05 1.03 1.18 0.80 1.33 1.29 1.12
3.34 1.54 0.08 0.12 0.60 0.72 0.92 1.05 1.43 3.05
1.81 2.17 0.63 0.56 0.03 0.09 0.18 0.34 1.51 1.45
1.52 0.19 1.55 0.02 0.07 0.65 0.40 0.24 1.51 1.45
1.60 1.80 4.69 0.08 7.89 1.58 1.64 0.03 0.23 0.72 (a) Find the range.

(b) Use a calculator to calculate ?x and ?x2. (Round your answers to two decimal places.)
?x =
?x2 =