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Finding the Fourth Proportional to 498.22, 687.88 and 311.80

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Solution

The fourth proportional to 498.22, 687.88 and 311.80 is: 430.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.22 : 687.88 = 311.80 : x
  2. Step 2: Convert to fraction form
    498.22/687.88 = 311.80/x
  3. Step 3: Cross multiply
    498.22x = 687.88 × 311.80
  4. Step 4: Simplify right side
    498.22x = 214,480.98
  5. Step 5: Solve for x
    x = 214,480.98/498.22
  6. Step 6: Final answer
    x = 430.49

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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.