Home / 820.20-1,131.88-470.90

Finding the Fourth Proportional to 820.20, 1,131.88 and 470.90

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Solution

The fourth proportional to 820.20, 1,131.88 and 470.90 is: 649.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.20 : 1,131.88 = 470.90 : x
  2. Step 2: Convert to fraction form
    820.20/1,131.88 = 470.90/x
  3. Step 3: Cross multiply
    820.20x = 1,131.88 × 470.90
  4. Step 4: Simplify right side
    820.20x = 533,002.29
  5. Step 5: Solve for x
    x = 533,002.29/820.20
  6. Step 6: Final answer
    x = 649.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.