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Finding the Fourth Proportional to 387.86, 581.72 and 127.85

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Solution

The fourth proportional to 387.86, 581.72 and 127.85 is: 191.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.86 : 581.72 = 127.85 : x
  2. Step 2: Convert to fraction form
    387.86/581.72 = 127.85/x
  3. Step 3: Cross multiply
    387.86x = 581.72 × 127.85
  4. Step 4: Simplify right side
    387.86x = 74,369.35
  5. Step 5: Solve for x
    x = 74,369.35/387.86
  6. Step 6: Final answer
    x = 191.75

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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.