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Finding the Fourth Proportional to 138.57, 206.80 and 123.19

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Solution

The fourth proportional to 138.57, 206.80 and 123.19 is: 183.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.57 : 206.80 = 123.19 : x
  2. Step 2: Convert to fraction form
    138.57/206.80 = 123.19/x
  3. Step 3: Cross multiply
    138.57x = 206.80 × 123.19
  4. Step 4: Simplify right side
    138.57x = 25,475.22
  5. Step 5: Solve for x
    x = 25,475.22/138.57
  6. Step 6: Final answer
    x = 183.85

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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.