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Finding the Fourth Proportional to 640.40, 882.18 and 557.36

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Solution

The fourth proportional to 640.40, 882.18 and 557.36 is: 767.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.40 : 882.18 = 557.36 : x
  2. Step 2: Convert to fraction form
    640.40/882.18 = 557.36/x
  3. Step 3: Cross multiply
    640.40x = 882.18 × 557.36
  4. Step 4: Simplify right side
    640.40x = 491,687.43
  5. Step 5: Solve for x
    x = 491,687.43/640.40
  6. Step 6: Final answer
    x = 767.79

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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.