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Finding the Fourth Proportional to 137.86, 206.58 and 86.56

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Solution

The fourth proportional to 137.86, 206.58 and 86.56 is: 129.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.86 : 206.58 = 86.56 : x
  2. Step 2: Convert to fraction form
    137.86/206.58 = 86.56/x
  3. Step 3: Cross multiply
    137.86x = 206.58 × 86.56
  4. Step 4: Simplify right side
    137.86x = 17,881.56
  5. Step 5: Solve for x
    x = 17,881.56/137.86
  6. Step 6: Final answer
    x = 129.71

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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.