Adiscrete random variable has a mean of 400 and a variance of 64. what is the standard deviation?

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

What is the similarity ratio of a cube with volume 729m^3 to a cube with volume 3375 m^3