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Finding the Fourth Proportional to 138.28, 189.54 and 138.05

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Solution

The fourth proportional to 138.28, 189.54 and 138.05 is: 189.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.28 : 189.54 = 138.05 : x
  2. Step 2: Convert to fraction form
    138.28/189.54 = 138.05/x
  3. Step 3: Cross multiply
    138.28x = 189.54 × 138.05
  4. Step 4: Simplify right side
    138.28x = 26,166.83
  5. Step 5: Solve for x
    x = 26,166.83/138.28
  6. Step 6: Final answer
    x = 189.23

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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.