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Finding the Fourth Proportional to 481.20, 721.80 and 308.40

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Solution

The fourth proportional to 481.20, 721.80 and 308.40 is: 462.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    481.20 : 721.80 = 308.40 : x
  2. Step 2: Convert to fraction form
    481.20/721.80 = 308.40/x
  3. Step 3: Cross multiply
    481.20x = 721.80 × 308.40
  4. Step 4: Simplify right side
    481.20x = 222,603.12
  5. Step 5: Solve for x
    x = 222,603.12/481.20
  6. Step 6: Final answer
    x = 462.60

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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.