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Finding the Fourth Proportional to 498.20, 686.79 and 387.45

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Solution

The fourth proportional to 498.20, 686.79 and 387.45 is: 534.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.20 : 686.79 = 387.45 : x
  2. Step 2: Convert to fraction form
    498.20/686.79 = 387.45/x
  3. Step 3: Cross multiply
    498.20x = 686.79 × 387.45
  4. Step 4: Simplify right side
    498.20x = 266,096.79
  5. Step 5: Solve for x
    x = 266,096.79/498.20
  6. Step 6: Final answer
    x = 534.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.