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Finding the Fourth Proportional to 81.74, 123.28 and 81.74

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Solution

The fourth proportional to 81.74, 123.28 and 81.74 is: 123.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.74 : 123.28 = 81.74 : x
  2. Step 2: Convert to fraction form
    81.74/123.28 = 81.74/x
  3. Step 3: Cross multiply
    81.74x = 123.28 × 81.74
  4. Step 4: Simplify right side
    81.74x = 10,076.91
  5. Step 5: Solve for x
    x = 10,076.91/81.74
  6. Step 6: Final answer
    x = 123.28

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.