The Grass Doctor

I need help on an example for Math Weighted Averages?

GRASS SEED A nursery sells Kentucky Blue Grass seed for $5.75 per pound and Tall Fescue seed for $4.50 per pound. The nursery sells a mixture of the two kinds of seed for $5.25 per pound. Let k represent the amount of Kentucky Blue Grass seed the nursery uses in 5 pounds of the mixture. a. Complete the table representing the problem. b. Write an equation to represent the problem. c. How much Kentucky Blue Grass does the nursery use in 5 pounds of the mixture? d. How much Tall Fescue does the nursery use in 5 pounds of the mixture?

Public Comments

1. a. I can't see the table, so I can't complete it. b. Let f = the fraction (in decimal) of KBG in the mixture. Therefore the fraction of TF in the mixture is 1-f. The amount of KBG in 5 lb of the mix (k) is then k = 5f. The equation to solve is: ($5.25)f + ($4.50)(1-f) = $5.25. c. Solving the equation, f = 0.6. Since k = 5f, k = 5 * 0.6 = 3 lbs. d. 5 - 3 = 2 lbs of TF in the mix.