Question

Scientists are monitoring a whale's weight by observing its weight change once a week, over a 4 week period. How much has the whale's weight changed over the entire 4 weeks?

Answer 1

Explanation:

-2.2 - (-1.7) - (-0.4) = -4.2 + 0.3 = -3.9

Answer 2

Option D. -3.9 will be the answer.

Explanation:

Change in weight of the whale in first week = (-2.1) pounds

Change in weight of the whale in second week = (+0.3) pounds

Change in weight of the whale in 3rd week = (-1.7) pounds

Change in weight of the whale in 4th week = -0.4 pounds

Total change in weight over the period of 4 weeks = - 2.1 + 0.3 - 1.7 - 0.4

= -3.9 pounds

Therefore, Option D. -3.9 will be the answer.