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Finding the Fourth Proportional to 142.87, 214.49 and 91.57

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Solution

The fourth proportional to 142.87, 214.49 and 91.57 is: 137.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.87 : 214.49 = 91.57 : x
  2. Step 2: Convert to fraction form
    142.87/214.49 = 91.57/x
  3. Step 3: Cross multiply
    142.87x = 214.49 × 91.57
  4. Step 4: Simplify right side
    142.87x = 19,640.85
  5. Step 5: Solve for x
    x = 19,640.85/142.87
  6. Step 6: Final answer
    x = 137.47

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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.