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Finding the Fourth Proportional to 539.60, 809.86 and 215.20

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Solution

The fourth proportional to 539.60, 809.86 and 215.20 is: 322.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    539.60 : 809.86 = 215.20 : x
  2. Step 2: Convert to fraction form
    539.60/809.86 = 215.20/x
  3. Step 3: Cross multiply
    539.60x = 809.86 × 215.20
  4. Step 4: Simplify right side
    539.60x = 174,281.87
  5. Step 5: Solve for x
    x = 174,281.87/539.60
  6. Step 6: Final answer
    x = 322.98

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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.