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Finding the Fourth Proportional to 387.72, 580.41 and 257.22

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Solution

The fourth proportional to 387.72, 580.41 and 257.22 is: 385.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.72 : 580.41 = 257.22 : x
  2. Step 2: Convert to fraction form
    387.72/580.41 = 257.22/x
  3. Step 3: Cross multiply
    387.72x = 580.41 × 257.22
  4. Step 4: Simplify right side
    387.72x = 149,293.06
  5. Step 5: Solve for x
    x = 149,293.06/387.72
  6. Step 6: Final answer
    x = 385.05

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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.