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Finding the Fourth Proportional to 486.38, 725.10 and 431.30

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Solution

The fourth proportional to 486.38, 725.10 and 431.30 is: 642.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.38 : 725.10 = 431.30 : x
  2. Step 2: Convert to fraction form
    486.38/725.10 = 431.30/x
  3. Step 3: Cross multiply
    486.38x = 725.10 × 431.30
  4. Step 4: Simplify right side
    486.38x = 312,735.63
  5. Step 5: Solve for x
    x = 312,735.63/486.38
  6. Step 6: Final answer
    x = 642.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.