Adistribution is positively skewed if which of these statements is true about the density curve that represents it?
a. the right tail is longer than the left.
b. the left tail is equal in length to the right tail.
c. the left side is a mirror reflection of the right side.
d. the left tail is longer than the right.

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

15.36 per mile

but forgot to round

i am pretty sure