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Finding the Fourth Proportional to 432.38, 648.47 and 212.78

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Solution

The fourth proportional to 432.38, 648.47 and 212.78 is: 319.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    432.38 : 648.47 = 212.78 : x
  2. Step 2: Convert to fraction form
    432.38/648.47 = 212.78/x
  3. Step 3: Cross multiply
    432.38x = 648.47 × 212.78
  4. Step 4: Simplify right side
    432.38x = 137,983.60
  5. Step 5: Solve for x
    x = 137,983.60/432.38
  6. Step 6: Final answer
    x = 319.12

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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.