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Finding the Fourth Proportional to 412.39, 618.60 and 123.85

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Solution

The fourth proportional to 412.39, 618.60 and 123.85 is: 185.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.39 : 618.60 = 123.85 : x
  2. Step 2: Convert to fraction form
    412.39/618.60 = 123.85/x
  3. Step 3: Cross multiply
    412.39x = 618.60 × 123.85
  4. Step 4: Simplify right side
    412.39x = 76,613.61
  5. Step 5: Solve for x
    x = 76,613.61/412.39
  6. Step 6: Final answer
    x = 185.78

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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.