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Finding the Fourth Proportional to 579.78, 801.21 and 439.78

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Solution

The fourth proportional to 579.78, 801.21 and 439.78 is: 607.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    579.78 : 801.21 = 439.78 : x
  2. Step 2: Convert to fraction form
    579.78/801.21 = 439.78/x
  3. Step 3: Cross multiply
    579.78x = 801.21 × 439.78
  4. Step 4: Simplify right side
    579.78x = 352,353.93
  5. Step 5: Solve for x
    x = 352,353.93/579.78
  6. Step 6: Final answer
    x = 607.74

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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.