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Finding the Fourth Proportional to 878.21, 1,211.92 and 479.87

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Solution

The fourth proportional to 878.21, 1,211.92 and 479.87 is: 662.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.21 : 1,211.92 = 479.87 : x
  2. Step 2: Convert to fraction form
    878.21/1,211.92 = 479.87/x
  3. Step 3: Cross multiply
    878.21x = 1,211.92 × 479.87
  4. Step 4: Simplify right side
    878.21x = 581,568.28
  5. Step 5: Solve for x
    x = 581,568.28/878.21
  6. Step 6: Final answer
    x = 662.22

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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.