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Finding the Fourth Proportional to 103.75, 154.78 and 90.89

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Solution

The fourth proportional to 103.75, 154.78 and 90.89 is: 135.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.75 : 154.78 = 90.89 : x
  2. Step 2: Convert to fraction form
    103.75/154.78 = 90.89/x
  3. Step 3: Cross multiply
    103.75x = 154.78 × 90.89
  4. Step 4: Simplify right side
    103.75x = 14,067.95
  5. Step 5: Solve for x
    x = 14,067.95/103.75
  6. Step 6: Final answer
    x = 135.59

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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.