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Finding the Fourth Proportional to 721.55, 1,081.42 and 310.20

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Solution

The fourth proportional to 721.55, 1,081.42 and 310.20 is: 464.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.55 : 1,081.42 = 310.20 : x
  2. Step 2: Convert to fraction form
    721.55/1,081.42 = 310.20/x
  3. Step 3: Cross multiply
    721.55x = 1,081.42 × 310.20
  4. Step 4: Simplify right side
    721.55x = 335,456.48
  5. Step 5: Solve for x
    x = 335,456.48/721.55
  6. Step 6: Final answer
    x = 464.91

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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.