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Finding the Fourth Proportional to 387.66, 580.79 and 257.36

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Solution

The fourth proportional to 387.66, 580.79 and 257.36 is: 385.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.66 : 580.79 = 257.36 : x
  2. Step 2: Convert to fraction form
    387.66/580.79 = 257.36/x
  3. Step 3: Cross multiply
    387.66x = 580.79 × 257.36
  4. Step 4: Simplify right side
    387.66x = 149,469.85
  5. Step 5: Solve for x
    x = 149,469.85/387.66
  6. Step 6: Final answer
    x = 385.57

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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.