Proving Proportionality Using Cross Multiplication

5/X=4/100 solve for X

• 100

• 125

• 5

• 4

• I dont know

Solve the proportion.
k/6 = 15 / 18

• k=5
• k=3.3333333
• k=60
• k=90

Solve using cross products:
5/6 = x/12

• x = 10
• x = 1
• x = 12
• x = 11

Use cross products to determine if these ratios are proportional:
4/5 = 3/4

• no
• yes

Solve the proportion.

• k=5
• k=3.3333333
• k=60
• k=90

Do the ratios form a proportion?

• Yes, they form a proportion.
• No, they do not form a proportion.

Use cross products to solve for the value of n. 
2/16 = 15/n

• n = 120
• n = 18
• n = 16
• n = 100

Solve for k

• 7/12
• 12/7
• 7
• 2

Solve for x

• 13
• 14
• 15
• 16