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Finding the Fourth Proportional to 81.37, 121.23 and 77.88

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Solution

The fourth proportional to 81.37, 121.23 and 77.88 is: 116.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.37 : 121.23 = 77.88 : x
  2. Step 2: Convert to fraction form
    81.37/121.23 = 77.88/x
  3. Step 3: Cross multiply
    81.37x = 121.23 × 77.88
  4. Step 4: Simplify right side
    81.37x = 9,441.17
  5. Step 5: Solve for x
    x = 9,441.17/81.37
  6. Step 6: Final answer
    x = 116.03

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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.