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Finding the Fourth Proportional to 387.60, 580.80 and 257.48

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Solution

The fourth proportional to 387.60, 580.80 and 257.48 is: 385.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.60 : 580.80 = 257.48 : x
  2. Step 2: Convert to fraction form
    387.60/580.80 = 257.48/x
  3. Step 3: Cross multiply
    387.60x = 580.80 × 257.48
  4. Step 4: Simplify right side
    387.60x = 149,544.38
  5. Step 5: Solve for x
    x = 149,544.38/387.60
  6. Step 6: Final answer
    x = 385.82

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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.