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Finding the Fourth Proportional to 138.10, 189.39 and 136.50

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Solution

The fourth proportional to 138.10, 189.39 and 136.50 is: 187.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.10 : 189.39 = 136.50 : x
  2. Step 2: Convert to fraction form
    138.10/189.39 = 136.50/x
  3. Step 3: Cross multiply
    138.10x = 189.39 × 136.50
  4. Step 4: Simplify right side
    138.10x = 25,851.74
  5. Step 5: Solve for x
    x = 25,851.74/138.10
  6. Step 6: Final answer
    x = 187.20

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.