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Finding the Fourth Proportional to 101.24, 139.64 and 81.80

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Solution

The fourth proportional to 101.24, 139.64 and 81.80 is: 112.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.24 : 139.64 = 81.80 : x
  2. Step 2: Convert to fraction form
    101.24/139.64 = 81.80/x
  3. Step 3: Cross multiply
    101.24x = 139.64 × 81.80
  4. Step 4: Simplify right side
    101.24x = 11,422.55
  5. Step 5: Solve for x
    x = 11,422.55/101.24
  6. Step 6: Final answer
    x = 112.83

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.