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Finding the Fourth Proportional to 257.87, 387.65 and 207.07

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Solution

The fourth proportional to 257.87, 387.65 and 207.07 is: 311.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.87 : 387.65 = 207.07 : x
  2. Step 2: Convert to fraction form
    257.87/387.65 = 207.07/x
  3. Step 3: Cross multiply
    257.87x = 387.65 × 207.07
  4. Step 4: Simplify right side
    257.87x = 80,270.69
  5. Step 5: Solve for x
    x = 80,270.69/257.87
  6. Step 6: Final answer
    x = 311.28

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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.