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Finding the Fourth Proportional to 257.20, 386.25 and 220.93

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Solution

The fourth proportional to 257.20, 386.25 and 220.93 is: 331.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.20 : 386.25 = 220.93 : x
  2. Step 2: Convert to fraction form
    257.20/386.25 = 220.93/x
  3. Step 3: Cross multiply
    257.20x = 386.25 × 220.93
  4. Step 4: Simplify right side
    257.20x = 85,334.21
  5. Step 5: Solve for x
    x = 85,334.21/257.20
  6. Step 6: Final answer
    x = 331.78

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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.