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Finding the Fourth Proportional to 138.97, 190.76 and 128.02

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Solution

The fourth proportional to 138.97, 190.76 and 128.02 is: 175.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.97 : 190.76 = 128.02 : x
  2. Step 2: Convert to fraction form
    138.97/190.76 = 128.02/x
  3. Step 3: Cross multiply
    138.97x = 190.76 × 128.02
  4. Step 4: Simplify right side
    138.97x = 24,421.10
  5. Step 5: Solve for x
    x = 24,421.10/138.97
  6. Step 6: Final answer
    x = 175.73

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.