1. which ratios form a proportion? a. 4/9, 12 / 25 b. 3 / 7, 18 / 42 c. 5/11, 20/45 d. 5/8, 15/25. 2. which ratio forms a proportion with 18 over 30? a. 20 / 35 b. 50 / 90 c. 36 / 48 d. 60 / 100. 3. which proportion has cross products of 5 × 24 and 8 × 15? a. 5/8=15/24 b. 5/24=8/15 c 8/24=15/5 d 15/8=5/24

Part 1)

Part 2)  

Part 3)

Step-by-step explanation:

we know that

If two ratios form a proportion, then the two ratios in simplest form are equal

Part 1

Which ratios form a proportion?

case A)

equate the ratios

------> is not true

therefore

the ratios case A does not form a proportion

case B)

equate the ratios

------> is true

therefore

the ratios case B  form a proportion

case C)

equate the ratios

------> is not true

therefore

the ratios case C does not form a proportion

case D)

equate the ratios

------> is not true

therefore

the ratios case D does not form a proportion

Part 2

Which ratio forms a proportion with 18 over 30?

case A)

equate the ratio to  

------> is not true

therefore

the ratio case A does not form a proportion with

case B)

equate the ratio to  

------> is not true

therefore

the ratio case B does not form a proportion with

case C)

equate the ratio to  

------> is not true

therefore

the ratio case C does not form a proportion with

case D)

equate the ratio to  

------> is true

therefore

the ratio case D  form a proportion with

Part 3

Which proportion has cross products of 5 × 24 and 8 × 15?

case A)

the cross product is equal to

therefore

the proportion case A is a solution

case B)

the cross product is equal to

therefore

the proportion case B is not a solution

case C)

the cross product is equal to

therefore

the proportion case C is not a solution

case D)

the cross product is equal to

therefore

the proportion case D is not a solution

step-by-step explanation: