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Finding the Fourth Proportional to 688.78, 949.71 and 557.38

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Solution

The fourth proportional to 688.78, 949.71 and 557.38 is: 768.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.78 : 949.71 = 557.38 : x
  2. Step 2: Convert to fraction form
    688.78/949.71 = 557.38/x
  3. Step 3: Cross multiply
    688.78x = 949.71 × 557.38
  4. Step 4: Simplify right side
    688.78x = 529,349.36
  5. Step 5: Solve for x
    x = 529,349.36/688.78
  6. Step 6: Final answer
    x = 768.53

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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.