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Finding the Fourth Proportional to 137.35, 189.61 and 107.78

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Solution

The fourth proportional to 137.35, 189.61 and 107.78 is: 148.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.35 : 189.61 = 107.78 : x
  2. Step 2: Convert to fraction form
    137.35/189.61 = 107.78/x
  3. Step 3: Cross multiply
    137.35x = 189.61 × 107.78
  4. Step 4: Simplify right side
    137.35x = 20,434.95
  5. Step 5: Solve for x
    x = 20,434.95/137.35
  6. Step 6: Final answer
    x = 148.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.