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Finding the Fourth Proportional to 639.60, 883.05 and 418.92

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Solution

The fourth proportional to 639.60, 883.05 and 418.92 is: 578.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.60 : 883.05 = 418.92 : x
  2. Step 2: Convert to fraction form
    639.60/883.05 = 418.92/x
  3. Step 3: Cross multiply
    639.60x = 883.05 × 418.92
  4. Step 4: Simplify right side
    639.60x = 369,927.31
  5. Step 5: Solve for x
    x = 369,927.31/639.60
  6. Step 6: Final answer
    x = 578.37

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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.