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Finding the Fourth Proportional to 458.78, 686.72 and 342.56

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Solution

The fourth proportional to 458.78, 686.72 and 342.56 is: 512.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.78 : 686.72 = 342.56 : x
  2. Step 2: Convert to fraction form
    458.78/686.72 = 342.56/x
  3. Step 3: Cross multiply
    458.78x = 686.72 × 342.56
  4. Step 4: Simplify right side
    458.78x = 235,240.23
  5. Step 5: Solve for x
    x = 235,240.23/458.78
  6. Step 6: Final answer
    x = 512.76

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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.