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Finding the Fourth Proportional to 498.20, 687.51 and 291.20

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Solution

The fourth proportional to 498.20, 687.51 and 291.20 is: 401.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.20 : 687.51 = 291.20 : x
  2. Step 2: Convert to fraction form
    498.20/687.51 = 291.20/x
  3. Step 3: Cross multiply
    498.20x = 687.51 × 291.20
  4. Step 4: Simplify right side
    498.20x = 200,202.91
  5. Step 5: Solve for x
    x = 200,202.91/498.20
  6. Step 6: Final answer
    x = 401.85

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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.