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Finding the Fourth Proportional to 138.21, 208.37 and 125.15

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Solution

The fourth proportional to 138.21, 208.37 and 125.15 is: 188.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.21 : 208.37 = 125.15 : x
  2. Step 2: Convert to fraction form
    138.21/208.37 = 125.15/x
  3. Step 3: Cross multiply
    138.21x = 208.37 × 125.15
  4. Step 4: Simplify right side
    138.21x = 26,076.78
  5. Step 5: Solve for x
    x = 26,076.78/138.21
  6. Step 6: Final answer
    x = 188.68

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.