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Finding the Fourth Proportional to 499.30, 688.57 and 312.73

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Solution

The fourth proportional to 499.30, 688.57 and 312.73 is: 431.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.30 : 688.57 = 312.73 : x
  2. Step 2: Convert to fraction form
    499.30/688.57 = 312.73/x
  3. Step 3: Cross multiply
    499.30x = 688.57 × 312.73
  4. Step 4: Simplify right side
    499.30x = 215,336.50
  5. Step 5: Solve for x
    x = 215,336.50/499.30
  6. Step 6: Final answer
    x = 431.28

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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.