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Finding the Fourth Proportional to 138.28, 189.15 and 138.28

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Solution

The fourth proportional to 138.28, 189.15 and 138.28 is: 189.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.28 : 189.15 = 138.28 : x
  2. Step 2: Convert to fraction form
    138.28/189.15 = 138.28/x
  3. Step 3: Cross multiply
    138.28x = 189.15 × 138.28
  4. Step 4: Simplify right side
    138.28x = 26,155.66
  5. Step 5: Solve for x
    x = 26,155.66/138.28
  6. Step 6: Final answer
    x = 189.15

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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.