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Finding the Fourth Proportional to 257.22, 385.86 and 103.20

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Solution

The fourth proportional to 257.22, 385.86 and 103.20 is: 154.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.22 : 385.86 = 103.20 : x
  2. Step 2: Convert to fraction form
    257.22/385.86 = 103.20/x
  3. Step 3: Cross multiply
    257.22x = 385.86 × 103.20
  4. Step 4: Simplify right side
    257.22x = 39,820.75
  5. Step 5: Solve for x
    x = 39,820.75/257.22
  6. Step 6: Final answer
    x = 154.81

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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.