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Finding the Fourth Proportional to 143.71, 215.55 and 81.97

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Solution

The fourth proportional to 143.71, 215.55 and 81.97 is: 122.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.71 : 215.55 = 81.97 : x
  2. Step 2: Convert to fraction form
    143.71/215.55 = 81.97/x
  3. Step 3: Cross multiply
    143.71x = 215.55 × 81.97
  4. Step 4: Simplify right side
    143.71x = 17,669.49
  5. Step 5: Solve for x
    x = 17,669.49/143.71
  6. Step 6: Final answer
    x = 122.95

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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.