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Finding the Fourth Proportional to 82.32, 122.88 and 81.36

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Solution

The fourth proportional to 82.32, 122.88 and 81.36 is: 121.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.32 : 122.88 = 81.36 : x
  2. Step 2: Convert to fraction form
    82.32/122.88 = 81.36/x
  3. Step 3: Cross multiply
    82.32x = 122.88 × 81.36
  4. Step 4: Simplify right side
    82.32x = 9,997.52
  5. Step 5: Solve for x
    x = 9,997.52/82.32
  6. Step 6: Final answer
    x = 121.45

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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.