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Finding the Fourth Proportional to 478.92, 721.34 and 445.12

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Solution

The fourth proportional to 478.92, 721.34 and 445.12 is: 670.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.92 : 721.34 = 445.12 : x
  2. Step 2: Convert to fraction form
    478.92/721.34 = 445.12/x
  3. Step 3: Cross multiply
    478.92x = 721.34 × 445.12
  4. Step 4: Simplify right side
    478.92x = 321,082.86
  5. Step 5: Solve for x
    x = 321,082.86/478.92
  6. Step 6: Final answer
    x = 670.43

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.