Question

The price of grapes at the grocery store is $1.44 per pound. There are approximately 0.45 kilograms in a pound. To the nearest cent, what is the price of grapes in dollars per kilogram?

$0.65 per kilogram
$0.99 per kilogram
$1.89 per kilogram
$3.20 per kilogram

Answer 1

the answer is number 4 or d

Answer 2

$3.20 / kg

Explanation:

$1.44 / pound

so, this is normed to 1 pound = 0.45 kg.

now we want to transform that to have 1 kg as the norming unit.

for this we need to multiply the top and the bottom of the ratio with the same number, so that the value of the ratio remains unchanged, but that the bottom turns into 1 kg.

so, what do we need to turn 0.45 into 1 ?

0.45 × x = 1

x = 1/0.45 = 1/1 / 45/100 = 100/45 = 20/9 = 2.22222...

since we need to multiply top and bottom with the same factor, we get

(1.44/0.45) × (2.222222/2.222222) =

(1.44 × 2.222222) / (0.45×2.222222) =

(1.44 × 2.222222) / 1kg = $3.20 / kg