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Finding the Fourth Proportional to 420.09, 631.12 and 396.78

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Solution

The fourth proportional to 420.09, 631.12 and 396.78 is: 596.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.09 : 631.12 = 396.78 : x
  2. Step 2: Convert to fraction form
    420.09/631.12 = 396.78/x
  3. Step 3: Cross multiply
    420.09x = 631.12 × 396.78
  4. Step 4: Simplify right side
    420.09x = 250,415.79
  5. Step 5: Solve for x
    x = 250,415.79/420.09
  6. Step 6: Final answer
    x = 596.10

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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.