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Finding the Fourth Proportional to 640.83, 883.94 and 392.05

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Solution

The fourth proportional to 640.83, 883.94 and 392.05 is: 540.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.83 : 883.94 = 392.05 : x
  2. Step 2: Convert to fraction form
    640.83/883.94 = 392.05/x
  3. Step 3: Cross multiply
    640.83x = 883.94 × 392.05
  4. Step 4: Simplify right side
    640.83x = 346,548.68
  5. Step 5: Solve for x
    x = 346,548.68/640.83
  6. Step 6: Final answer
    x = 540.78

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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.