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Finding the Fourth Proportional to 638.38, 878.80 and 572.86

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Solution

The fourth proportional to 638.38, 878.80 and 572.86 is: 788.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.38 : 878.80 = 572.86 : x
  2. Step 2: Convert to fraction form
    638.38/878.80 = 572.86/x
  3. Step 3: Cross multiply
    638.38x = 878.80 × 572.86
  4. Step 4: Simplify right side
    638.38x = 503,422.11
  5. Step 5: Solve for x
    x = 503,422.11/638.38
  6. Step 6: Final answer
    x = 788.60

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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.