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Finding the Fourth Proportional to 256.97, 386.27 and 213.90

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Solution

The fourth proportional to 256.97, 386.27 and 213.90 is: 321.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.97 : 386.27 = 213.90 : x
  2. Step 2: Convert to fraction form
    256.97/386.27 = 213.90/x
  3. Step 3: Cross multiply
    256.97x = 386.27 × 213.90
  4. Step 4: Simplify right side
    256.97x = 82,622.08
  5. Step 5: Solve for x
    x = 82,622.08/256.97
  6. Step 6: Final answer
    x = 321.53

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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.