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Finding the Fourth Proportional to 678.78, 935.96 and 499.28

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Solution

The fourth proportional to 678.78, 935.96 and 499.28 is: 688.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.78 : 935.96 = 499.28 : x
  2. Step 2: Convert to fraction form
    678.78/935.96 = 499.28/x
  3. Step 3: Cross multiply
    678.78x = 935.96 × 499.28
  4. Step 4: Simplify right side
    678.78x = 467,298.93
  5. Step 5: Solve for x
    x = 467,298.93/678.78
  6. Step 6: Final answer
    x = 688.44

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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.