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Finding the Fourth Proportional to 458.28, 686.34 and 387

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Solution

The fourth proportional to 458.28, 686.34 and 387 is: 579.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.28 : 686.34 = 387 : x
  2. Step 2: Convert to fraction form
    458.28/686.34 = 387/x
  3. Step 3: Cross multiply
    458.28x = 686.34 × 387
  4. Step 4: Simplify right side
    458.28x = 265,613.58
  5. Step 5: Solve for x
    x = 265,613.58/458.28
  6. Step 6: Final answer
    x = 579.59

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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.