Help me on this assignment I need it for a grade

P= $1400,300 r = 7 1/2% t = 4 what is i ? $4.29 $429.00 $4290.00

Use the x-intercept method to find all real solutions of the equation. -9x^3-7x^2-96x+36=3x^3+x^2-3x+8

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.