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Finding the Fourth Proportional to 458.40, 687.76 and 425.76

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Solution

The fourth proportional to 458.40, 687.76 and 425.76 is: 638.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.40 : 687.76 = 425.76 : x
  2. Step 2: Convert to fraction form
    458.40/687.76 = 425.76/x
  3. Step 3: Cross multiply
    458.40x = 687.76 × 425.76
  4. Step 4: Simplify right side
    458.40x = 292,820.70
  5. Step 5: Solve for x
    x = 292,820.70/458.40
  6. Step 6: Final answer
    x = 638.79

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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.