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Finding the Fourth Proportional to 498.36, 687.86 and 311.85

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Solution

The fourth proportional to 498.36, 687.86 and 311.85 is: 430.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.36 : 687.86 = 311.85 : x
  2. Step 2: Convert to fraction form
    498.36/687.86 = 311.85/x
  3. Step 3: Cross multiply
    498.36x = 687.86 × 311.85
  4. Step 4: Simplify right side
    498.36x = 214,507.58
  5. Step 5: Solve for x
    x = 214,507.58/498.36
  6. Step 6: Final answer
    x = 430.43

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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.