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Finding the Fourth Proportional to 403.78, 605.63 and 129.88

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Solution

The fourth proportional to 403.78, 605.63 and 129.88 is: 194.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.78 : 605.63 = 129.88 : x
  2. Step 2: Convert to fraction form
    403.78/605.63 = 129.88/x
  3. Step 3: Cross multiply
    403.78x = 605.63 × 129.88
  4. Step 4: Simplify right side
    403.78x = 78,659.22
  5. Step 5: Solve for x
    x = 78,659.22/403.78
  6. Step 6: Final answer
    x = 194.81

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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.