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Finding the Fourth Proportional to 138.77, 208.86 and 104.70

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Solution

The fourth proportional to 138.77, 208.86 and 104.70 is: 157.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.77 : 208.86 = 104.70 : x
  2. Step 2: Convert to fraction form
    138.77/208.86 = 104.70/x
  3. Step 3: Cross multiply
    138.77x = 208.86 × 104.70
  4. Step 4: Simplify right side
    138.77x = 21,867.64
  5. Step 5: Solve for x
    x = 21,867.64/138.77
  6. Step 6: Final answer
    x = 157.59

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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.