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Finding the Fourth Proportional to 429.92, 645.12 and 407.68

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Solution

The fourth proportional to 429.92, 645.12 and 407.68 is: 611.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.92 : 645.12 = 407.68 : x
  2. Step 2: Convert to fraction form
    429.92/645.12 = 407.68/x
  3. Step 3: Cross multiply
    429.92x = 645.12 × 407.68
  4. Step 4: Simplify right side
    429.92x = 263,002.52
  5. Step 5: Solve for x
    x = 263,002.52/429.92
  6. Step 6: Final answer
    x = 611.75

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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.