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Finding the Fourth Proportional to 81.06, 121.59 and 69.63

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Solution

The fourth proportional to 81.06, 121.59 and 69.63 is: 104.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.06 : 121.59 = 69.63 : x
  2. Step 2: Convert to fraction form
    81.06/121.59 = 69.63/x
  3. Step 3: Cross multiply
    81.06x = 121.59 × 69.63
  4. Step 4: Simplify right side
    81.06x = 8,466.31
  5. Step 5: Solve for x
    x = 8,466.31/81.06
  6. Step 6: Final answer
    x = 104.45

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.