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Finding the Fourth Proportional to 257.30, 385.84 and 103.21

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Solution

The fourth proportional to 257.30, 385.84 and 103.21 is: 154.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.30 : 385.84 = 103.21 : x
  2. Step 2: Convert to fraction form
    257.30/385.84 = 103.21/x
  3. Step 3: Cross multiply
    257.30x = 385.84 × 103.21
  4. Step 4: Simplify right side
    257.30x = 39,822.55
  5. Step 5: Solve for x
    x = 39,822.55/257.30
  6. Step 6: Final answer
    x = 154.77

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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.