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Finding the Fourth Proportional to 638.87, 885.47 and 627.21

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Solution

The fourth proportional to 638.87, 885.47 and 627.21 is: 869.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.87 : 885.47 = 627.21 : x
  2. Step 2: Convert to fraction form
    638.87/885.47 = 627.21/x
  3. Step 3: Cross multiply
    638.87x = 885.47 × 627.21
  4. Step 4: Simplify right side
    638.87x = 555,372.50
  5. Step 5: Solve for x
    x = 555,372.50/638.87
  6. Step 6: Final answer
    x = 869.31

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.