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Finding the Fourth Proportional to 439.72, 660.20 and 386.26

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Solution

The fourth proportional to 439.72, 660.20 and 386.26 is: 579.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.72 : 660.20 = 386.26 : x
  2. Step 2: Convert to fraction form
    439.72/660.20 = 386.26/x
  3. Step 3: Cross multiply
    439.72x = 660.20 × 386.26
  4. Step 4: Simplify right side
    439.72x = 255,008.85
  5. Step 5: Solve for x
    x = 255,008.85/439.72
  6. Step 6: Final answer
    x = 579.93

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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.