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Finding the Fourth Proportional to 403.86, 605.49 and 129.78

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Solution

The fourth proportional to 403.86, 605.49 and 129.78 is: 194.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.86 : 605.49 = 129.78 : x
  2. Step 2: Convert to fraction form
    403.86/605.49 = 129.78/x
  3. Step 3: Cross multiply
    403.86x = 605.49 × 129.78
  4. Step 4: Simplify right side
    403.86x = 78,580.49
  5. Step 5: Solve for x
    x = 78,580.49/403.86
  6. Step 6: Final answer
    x = 194.57

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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.