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Finding the Fourth Proportional to 103.09, 154.36 and 81.23

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Solution

The fourth proportional to 103.09, 154.36 and 81.23 is: 121.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.09 : 154.36 = 81.23 : x
  2. Step 2: Convert to fraction form
    103.09/154.36 = 81.23/x
  3. Step 3: Cross multiply
    103.09x = 154.36 × 81.23
  4. Step 4: Simplify right side
    103.09x = 12,538.66
  5. Step 5: Solve for x
    x = 12,538.66/103.09
  6. Step 6: Final answer
    x = 121.63

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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.