Can someone me create a polynomial that meets these criteria?

--a maximum of 3 roots
--exactly 1 x-intercept
--exactly 2 different intervals of increase
--no more than 10 possible rational roots

The depreciation per unit for a company

Find the slope and the y-intercept if there's one and the equation of the line given these two points( 3, 2) and( 3, -4)

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?