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Finding the Fourth Proportional to 809.20, 1,212.54 and 520.06

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Solution

The fourth proportional to 809.20, 1,212.54 and 520.06 is: 779.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.20 : 1,212.54 = 520.06 : x
  2. Step 2: Convert to fraction form
    809.20/1,212.54 = 520.06/x
  3. Step 3: Cross multiply
    809.20x = 1,212.54 × 520.06
  4. Step 4: Simplify right side
    809.20x = 630,593.55
  5. Step 5: Solve for x
    x = 630,593.55/809.20
  6. Step 6: Final answer
    x = 779.28

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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.