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Finding the Fourth Proportional to 138.30, 206.13 and 123.87

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Solution

The fourth proportional to 138.30, 206.13 and 123.87 is: 184.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.30 : 206.13 = 123.87 : x
  2. Step 2: Convert to fraction form
    138.30/206.13 = 123.87/x
  3. Step 3: Cross multiply
    138.30x = 206.13 × 123.87
  4. Step 4: Simplify right side
    138.30x = 25,533.32
  5. Step 5: Solve for x
    x = 25,533.32/138.30
  6. Step 6: Final answer
    x = 184.62

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.