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Finding the Fourth Proportional to 81.56, 121.60 and 75.48

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Solution

The fourth proportional to 81.56, 121.60 and 75.48 is: 112.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.56 : 121.60 = 75.48 : x
  2. Step 2: Convert to fraction form
    81.56/121.60 = 75.48/x
  3. Step 3: Cross multiply
    81.56x = 121.60 × 75.48
  4. Step 4: Simplify right side
    81.56x = 9,178.37
  5. Step 5: Solve for x
    x = 9,178.37/81.56
  6. Step 6: Final answer
    x = 112.54

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.