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Finding the Fourth Proportional to 498.30, 687.81 and 311.69

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Solution

The fourth proportional to 498.30, 687.81 and 311.69 is: 430.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.30 : 687.81 = 311.69 : x
  2. Step 2: Convert to fraction form
    498.30/687.81 = 311.69/x
  3. Step 3: Cross multiply
    498.30x = 687.81 × 311.69
  4. Step 4: Simplify right side
    498.30x = 214,380.06
  5. Step 5: Solve for x
    x = 214,380.06/498.30
  6. Step 6: Final answer
    x = 430.22

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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.