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Finding the Fourth Proportional to 387.91, 581.03 and 257.97

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Solution

The fourth proportional to 387.91, 581.03 and 257.97 is: 386.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.91 : 581.03 = 257.97 : x
  2. Step 2: Convert to fraction form
    387.91/581.03 = 257.97/x
  3. Step 3: Cross multiply
    387.91x = 581.03 × 257.97
  4. Step 4: Simplify right side
    387.91x = 149,888.31
  5. Step 5: Solve for x
    x = 149,888.31/387.91
  6. Step 6: Final answer
    x = 386.40

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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.