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Finding the Fourth Proportional to 138.40, 190.94 and 80.16

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Solution

The fourth proportional to 138.40, 190.94 and 80.16 is: 110.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.40 : 190.94 = 80.16 : x
  2. Step 2: Convert to fraction form
    138.40/190.94 = 80.16/x
  3. Step 3: Cross multiply
    138.40x = 190.94 × 80.16
  4. Step 4: Simplify right side
    138.40x = 15,305.75
  5. Step 5: Solve for x
    x = 15,305.75/138.40
  6. Step 6: Final answer
    x = 110.59

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.