There is a proportinal relationship between the volume of a sample of helium in liters and the mass of that sample in grams. if the mass of a sample is 5 grams, its volume is 28 liters. (5, 28) is shown on the graph below. what is the constant of proportionality in this relationship plz help

Samantha is growing a garden in her back yard. she spend $90 setting up the garden bed and buying the proper garden supplies. in addition, each seed she plants cost $0.25. a. write the function f(x) that represents samantha's total cost on her garden. b. explain what x represents. c. explain what f(x) represents. d. if samantha plants 55 seeds, how much did she spend in total?