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Finding the Fourth Proportional to 638.72, 881.31 and 376.66

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Solution

The fourth proportional to 638.72, 881.31 and 376.66 is: 519.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.72 : 881.31 = 376.66 : x
  2. Step 2: Convert to fraction form
    638.72/881.31 = 376.66/x
  3. Step 3: Cross multiply
    638.72x = 881.31 × 376.66
  4. Step 4: Simplify right side
    638.72x = 331,954.22
  5. Step 5: Solve for x
    x = 331,954.22/638.72
  6. Step 6: Final answer
    x = 519.72

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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.