Isabel sells new and used mystery novels online. Her customers are primarily in the United States. She sends up to 10 pounds of books in one shipment. She uses the United States Postal Service’s Media Mail service because it is inexpensive for her customers. Current Media Mail shipping prices for book shipments weighing 10 pounds or less appear below. (picture above). How much would it cost to ship a package weighing 3.2 pounds? Explain how you arrived at your answer.

23

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

answer: your correct answer is b. d.

step-by-step explanation: