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Finding the Fourth Proportional to 103.25, 154.91 and 80.51

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Solution

The fourth proportional to 103.25, 154.91 and 80.51 is: 120.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.25 : 154.91 = 80.51 : x
  2. Step 2: Convert to fraction form
    103.25/154.91 = 80.51/x
  3. Step 3: Cross multiply
    103.25x = 154.91 × 80.51
  4. Step 4: Simplify right side
    103.25x = 12,471.23
  5. Step 5: Solve for x
    x = 12,471.23/103.25
  6. Step 6: Final answer
    x = 120.78

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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.