How to find the mean absolute deviation?

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Is a positive integer raised to a negative power always positive

Find the value. a. 0.003 b. 0.03 c. 0.3 d. 3