Home / 808.80-1,213.20-646.80

Finding the Fourth Proportional to 808.80, 1,213.20 and 646.80

Calculator

Solution

The fourth proportional to 808.80, 1,213.20 and 646.80 is: 970.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.80 : 1,213.20 = 646.80 : x
  2. Step 2: Convert to fraction form
    808.80/1,213.20 = 646.80/x
  3. Step 3: Cross multiply
    808.80x = 1,213.20 × 646.80
  4. Step 4: Simplify right side
    808.80x = 784,697.76
  5. Step 5: Solve for x
    x = 784,697.76/808.80
  6. Step 6: Final answer
    x = 970.20

Related Problems

Find fourth proportional to 404.40, 606.60 and 323.40
Half scale
Find fourth proportional to 1,617.60, 2,426.40 and 1,293.60
Double scale
Find fourth proportional to 809.80, 1,214.70 and 647.80
Similar ratio
Find fourth proportional to 1,213.20, 1,819.80 and 970.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.