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Finding the Fourth Proportional to 640, 882.84 and 391.44

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Solution

The fourth proportional to 640, 882.84 and 391.44 is: 539.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 882.84 = 391.44 : x
  2. Step 2: Convert to fraction form
    640/882.84 = 391.44/x
  3. Step 3: Cross multiply
    640x = 882.84 × 391.44
  4. Step 4: Simplify right side
    640x = 345,578.89
  5. Step 5: Solve for x
    x = 345,578.89/640
  6. Step 6: Final answer
    x = 539.97

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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.