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Finding the Fourth Proportional to 498.72, 687.90 and 386.97

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Solution

The fourth proportional to 498.72, 687.90 and 386.97 is: 533.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.72 : 687.90 = 386.97 : x
  2. Step 2: Convert to fraction form
    498.72/687.90 = 386.97/x
  3. Step 3: Cross multiply
    498.72x = 687.90 × 386.97
  4. Step 4: Simplify right side
    498.72x = 266,194.73
  5. Step 5: Solve for x
    x = 266,194.73/498.72
  6. Step 6: Final answer
    x = 533.76

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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.