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Finding the Fourth Proportional to 539.78, 809.76 and 215.15

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Solution

The fourth proportional to 539.78, 809.76 and 215.15 is: 322.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    539.78 : 809.76 = 215.15 : x
  2. Step 2: Convert to fraction form
    539.78/809.76 = 215.15/x
  3. Step 3: Cross multiply
    539.78x = 809.76 × 215.15
  4. Step 4: Simplify right side
    539.78x = 174,219.86
  5. Step 5: Solve for x
    x = 174,219.86/539.78
  6. Step 6: Final answer
    x = 322.76

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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.