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Finding the Fourth Proportional to 253.90, 380.87 and 80.57

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Solution

The fourth proportional to 253.90, 380.87 and 80.57 is: 120.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.90 : 380.87 = 80.57 : x
  2. Step 2: Convert to fraction form
    253.90/380.87 = 80.57/x
  3. Step 3: Cross multiply
    253.90x = 380.87 × 80.57
  4. Step 4: Simplify right side
    253.90x = 30,687.55
  5. Step 5: Solve for x
    x = 30,687.55/253.90
  6. Step 6: Final answer
    x = 120.87

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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.