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Finding the Fourth Proportional to 257.86, 387.09 and 207.13

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Solution

The fourth proportional to 257.86, 387.09 and 207.13 is: 310.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.86 : 387.09 = 207.13 : x
  2. Step 2: Convert to fraction form
    257.86/387.09 = 207.13/x
  3. Step 3: Cross multiply
    257.86x = 387.09 × 207.13
  4. Step 4: Simplify right side
    257.86x = 80,177.95
  5. Step 5: Solve for x
    x = 80,177.95/257.86
  6. Step 6: Final answer
    x = 310.94

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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.