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Finding the Fourth Proportional to 137.28, 189.68 and 108.12

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Solution

The fourth proportional to 137.28, 189.68 and 108.12 is: 149.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.28 : 189.68 = 108.12 : x
  2. Step 2: Convert to fraction form
    137.28/189.68 = 108.12/x
  3. Step 3: Cross multiply
    137.28x = 189.68 × 108.12
  4. Step 4: Simplify right side
    137.28x = 20,507.66
  5. Step 5: Solve for x
    x = 20,507.66/137.28
  6. Step 6: Final answer
    x = 149.39

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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.