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Finding the Fourth Proportional to 640.02, 882.84 and 391.44

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Solution

The fourth proportional to 640.02, 882.84 and 391.44 is: 539.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.02 : 882.84 = 391.44 : x
  2. Step 2: Convert to fraction form
    640.02/882.84 = 391.44/x
  3. Step 3: Cross multiply
    640.02x = 882.84 × 391.44
  4. Step 4: Simplify right side
    640.02x = 345,578.89
  5. Step 5: Solve for x
    x = 345,578.89/640.02
  6. Step 6: Final answer
    x = 539.95

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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.