The lengths of salamanders have a normal distribution with mean 15cm, and standard deviation 2cm.

What is the probability a salamander has length less than 13cm?

(provide your answer as a decimal)

Answer asap! show all work! find the number of complex roots, the possible number of real roots and the possible rational roots of the polynomial function. then, solve for all roots. x^3 + 2x^2 + 3x + 6 = 0