The following are possible ways to express the quantity 0.391 (give all correct answers, i. e., b, ac, note: 3.45e-8 is a way you can enter the number 3.45×10-8 in most computers. a) 0.000391e4 b) 39.1 x 10-1 c) 0.391e+1 d) 3.91e-1 e) 0.0391e+1 f) 0.00391 x 102

To answer, evaluate the power of 10 in the given choices. If it is positve, move the decimal n places to the right. If it is negative, move the decimal n corresponding places to the left. From all the choices given, only the choices D, E, and F will give us the correct answer.