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Finding the Fourth Proportional to 190.87, 286.23 and 81.20

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Solution

The fourth proportional to 190.87, 286.23 and 81.20 is: 121.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.87 : 286.23 = 81.20 : x
  2. Step 2: Convert to fraction form
    190.87/286.23 = 81.20/x
  3. Step 3: Cross multiply
    190.87x = 286.23 × 81.20
  4. Step 4: Simplify right side
    190.87x = 23,242.90
  5. Step 5: Solve for x
    x = 23,242.90/190.87
  6. Step 6: Final answer
    x = 121.77

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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.