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Finding the Fourth Proportional to 138.02, 206.61 and 115.26

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Solution

The fourth proportional to 138.02, 206.61 and 115.26 is: 172.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.02 : 206.61 = 115.26 : x
  2. Step 2: Convert to fraction form
    138.02/206.61 = 115.26/x
  3. Step 3: Cross multiply
    138.02x = 206.61 × 115.26
  4. Step 4: Simplify right side
    138.02x = 23,813.87
  5. Step 5: Solve for x
    x = 23,813.87/138.02
  6. Step 6: Final answer
    x = 172.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.