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Finding the Fourth Proportional to 456.60, 686.42 and 422.78

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Solution

The fourth proportional to 456.60, 686.42 and 422.78 is: 635.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.60 : 686.42 = 422.78 : x
  2. Step 2: Convert to fraction form
    456.60/686.42 = 422.78/x
  3. Step 3: Cross multiply
    456.60x = 686.42 × 422.78
  4. Step 4: Simplify right side
    456.60x = 290,202.53
  5. Step 5: Solve for x
    x = 290,202.53/456.60
  6. Step 6: Final answer
    x = 635.57

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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.