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Finding the Fourth Proportional to 387.46, 581.39 and 257.55

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Solution

The fourth proportional to 387.46, 581.39 and 257.55 is: 386.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.46 : 581.39 = 257.55 : x
  2. Step 2: Convert to fraction form
    387.46/581.39 = 257.55/x
  3. Step 3: Cross multiply
    387.46x = 581.39 × 257.55
  4. Step 4: Simplify right side
    387.46x = 149,735.10
  5. Step 5: Solve for x
    x = 149,735.10/387.46
  6. Step 6: Final answer
    x = 386.45

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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.