Help please

Bob the builder is making 480kg of cement mix. this is made by cement, sand and gravel in the ratio 1: 3: 4

Percy rides his bike 11.2 miles in 1.4 hours at a constant rate. write an equation to represent the proportional relationship between the number of hours percy rides, x, and the distance in miles, y, that he travels.

Juanita wade's new car has an msrp of $28,902.11 including title and processing fees. the premier package which includes surround sound and dvd player costs three times the amount of the in-style package which includes leather seats and select wheels. the total cost of her new car was $34,290.08 which included the 6.5% sales tax. find the cost of the premier package to the nearest cent.