At the beginning of an experiment, there are 400 grams of contaminants. each hour, three-fourths of the contaminants are filtered out. a. formulate a recursive sequence modeling the number of grams after n hours. b. use the model to calculate the amount of contaminants after the third hour of the experiment.

We have that

A).Formulate a recursive sequence modeling the number of grams after n hours.
a(n) = 0.75*a(n-1)

B) .Use the model to calculate the amount of contaminants after the third hour of the experiment. 
 for the first hour
a(1) = 0.75*a(0)
a0=400 g
 a1=(3/4)400 = 300 g

for the second hour
a(2) = 0.75*a(1)
a1=300 g
a2=(3/4)300 = 900/4 g

for the third hour
a(3) = 0.75*a(2)
a2=900/4 g
(3/4)900/4 = 2700/16 = 168.75 g

 the answer is 168.75 g

Ithink the answer is a

Ifound this on google “a skewed (non-symmetric) distribution is a distribution in which there is no such mirror-imaging. a "skewed right" distribution is one in which the tail is on the right side. a "skewed left" distribution is one in which the tail is on the left side. the above histogram is for a distribution that is skewed right.” i hope this you for what your looking for