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Finding the Fourth Proportional to 640.82, 884.31 and 392.15

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Solution

The fourth proportional to 640.82, 884.31 and 392.15 is: 541.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.82 : 884.31 = 392.15 : x
  2. Step 2: Convert to fraction form
    640.82/884.31 = 392.15/x
  3. Step 3: Cross multiply
    640.82x = 884.31 × 392.15
  4. Step 4: Simplify right side
    640.82x = 346,782.17
  5. Step 5: Solve for x
    x = 346,782.17/640.82
  6. Step 6: Final answer
    x = 541.15

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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.