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Finding the Fourth Proportional to 387.84, 581.78 and 127.85

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Solution

The fourth proportional to 387.84, 581.78 and 127.85 is: 191.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.84 : 581.78 = 127.85 : x
  2. Step 2: Convert to fraction form
    387.84/581.78 = 127.85/x
  3. Step 3: Cross multiply
    387.84x = 581.78 × 127.85
  4. Step 4: Simplify right side
    387.84x = 74,382.89
  5. Step 5: Solve for x
    x = 74,382.89/387.84
  6. Step 6: Final answer
    x = 191.79

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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.