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Finding the Fourth Proportional to 498.86, 688.10 and 312.15

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Solution

The fourth proportional to 498.86, 688.10 and 312.15 is: 430.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.86 : 688.10 = 312.15 : x
  2. Step 2: Convert to fraction form
    498.86/688.10 = 312.15/x
  3. Step 3: Cross multiply
    498.86x = 688.10 × 312.15
  4. Step 4: Simplify right side
    498.86x = 214,788.85
  5. Step 5: Solve for x
    x = 214,788.85/498.86
  6. Step 6: Final answer
    x = 430.56

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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.