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Finding the Fourth Proportional to 639.43, 881.58 and 418.30

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Solution

The fourth proportional to 639.43, 881.58 and 418.30 is: 576.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.43 : 881.58 = 418.30 : x
  2. Step 2: Convert to fraction form
    639.43/881.58 = 418.30/x
  3. Step 3: Cross multiply
    639.43x = 881.58 × 418.30
  4. Step 4: Simplify right side
    639.43x = 368,764.28
  5. Step 5: Solve for x
    x = 368,764.28/639.43
  6. Step 6: Final answer
    x = 576.71

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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.