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Finding the Fourth Proportional to 499.39, 688.96 and 312.80

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Solution

The fourth proportional to 499.39, 688.96 and 312.80 is: 431.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.39 : 688.96 = 312.80 : x
  2. Step 2: Convert to fraction form
    499.39/688.96 = 312.80/x
  3. Step 3: Cross multiply
    499.39x = 688.96 × 312.80
  4. Step 4: Simplify right side
    499.39x = 215,503.24
  5. Step 5: Solve for x
    x = 215,503.24/499.39
  6. Step 6: Final answer
    x = 431.54

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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.