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Finding the Fourth Proportional to 878.87, 1,317.49 and 391.66

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Solution

The fourth proportional to 878.87, 1,317.49 and 391.66 is: 587.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.87 : 1,317.49 = 391.66 : x
  2. Step 2: Convert to fraction form
    878.87/1,317.49 = 391.66/x
  3. Step 3: Cross multiply
    878.87x = 1,317.49 × 391.66
  4. Step 4: Simplify right side
    878.87x = 516,003.86
  5. Step 5: Solve for x
    x = 516,003.86/878.87
  6. Step 6: Final answer
    x = 587.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.