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Finding the Fourth Proportional to 439.68, 606.72 and 309.12

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Solution

The fourth proportional to 439.68, 606.72 and 309.12 is: 426.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.68 : 606.72 = 309.12 : x
  2. Step 2: Convert to fraction form
    439.68/606.72 = 309.12/x
  3. Step 3: Cross multiply
    439.68x = 606.72 × 309.12
  4. Step 4: Simplify right side
    439.68x = 187,549.29
  5. Step 5: Solve for x
    x = 187,549.29/439.68
  6. Step 6: Final answer
    x = 426.56

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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.