Extra Example 2 A 6-pound bag of cat food costs $12.84.
A 16-pound bag of cat food costs $33.92.
Which bag of cat food is the better buy?
Bag is the better buy; because
it costs per pound and bag
costs
per pound
Replace the line
with the correct
answers

A 6-pound bag of cat food is the better buy, because it costs $2.14 per pound and bag costs $12.84.

I got $2.14 by dividing 6 from $12.84.

However, I don’t know if it’s correct, but I hope you get the answer correct.

270 books in each shelves

a. geometricb. g[h] = (3/4)·g[h-1]; g[1] = 384c. g[h] = 384·(3/4)^(h-1)d. g[12] ≈ 16.2183 gallonse. g[12] ≈ 64.8732 quarts

step-by-step explanation:

part a. the differences are decreasing, so we know the sequence is not arithmetic. the ratios are constant (=3/4), so we know the sequence is geometric.

part b. from part a, we know the common ratio is 3/4, so each term is 3/4 of the one before. the initial term is the number of gallons at h=1.

g[h] = (3/4)·g[h-1]

g[1] = 384 . . . . initial value required for a recursive definition

part c. the general formula for a geometric sequence is

a[n] = a[1]·r^(n-1)

we have a[1] = 384, r = 3/4, and the term number given by h. the formula that follows is

g[h] = 384·(3/4)^(h-1)

part d. filling in the value and doing the arithmetic, we have

g[12] = 384·(3/4)^11 ≈ 384·0.042235136 ≈ 16.2183 . . gallons

part e. each gallon is 4 quarts, so

16.2183 gal × 4 qt/gal = 64.8732 qt