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Finding the Fourth Proportional to 103.86, 155.07 and 91.56

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Solution

The fourth proportional to 103.86, 155.07 and 91.56 is: 136.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.86 : 155.07 = 91.56 : x
  2. Step 2: Convert to fraction form
    103.86/155.07 = 91.56/x
  3. Step 3: Cross multiply
    103.86x = 155.07 × 91.56
  4. Step 4: Simplify right side
    103.86x = 14,198.21
  5. Step 5: Solve for x
    x = 14,198.21/103.86
  6. Step 6: Final answer
    x = 136.71

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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.