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Finding the Fourth Proportional to 137.79, 206.73 and 86.36

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Solution

The fourth proportional to 137.79, 206.73 and 86.36 is: 129.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.79 : 206.73 = 86.36 : x
  2. Step 2: Convert to fraction form
    137.79/206.73 = 86.36/x
  3. Step 3: Cross multiply
    137.79x = 206.73 × 86.36
  4. Step 4: Simplify right side
    137.79x = 17,852.62
  5. Step 5: Solve for x
    x = 17,852.62/137.79
  6. Step 6: Final answer
    x = 129.56

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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.