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Finding the Fourth Proportional to 498.08, 687.20 and 311.60

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Solution

The fourth proportional to 498.08, 687.20 and 311.60 is: 429.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.08 : 687.20 = 311.60 : x
  2. Step 2: Convert to fraction form
    498.08/687.20 = 311.60/x
  3. Step 3: Cross multiply
    498.08x = 687.20 × 311.60
  4. Step 4: Simplify right side
    498.08x = 214,131.52
  5. Step 5: Solve for x
    x = 214,131.52/498.08
  6. Step 6: Final answer
    x = 429.91

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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.