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Finding the Fourth Proportional to 439.80, 660.38 and 420.32

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Solution

The fourth proportional to 439.80, 660.38 and 420.32 is: 631.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.80 : 660.38 = 420.32 : x
  2. Step 2: Convert to fraction form
    439.80/660.38 = 420.32/x
  3. Step 3: Cross multiply
    439.80x = 660.38 × 420.32
  4. Step 4: Simplify right side
    439.80x = 277,570.92
  5. Step 5: Solve for x
    x = 277,570.92/439.80
  6. Step 6: Final answer
    x = 631.13

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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.