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Finding the Fourth Proportional to 137.97, 205.81 and 128.15

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Solution

The fourth proportional to 137.97, 205.81 and 128.15 is: 191.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.97 : 205.81 = 128.15 : x
  2. Step 2: Convert to fraction form
    137.97/205.81 = 128.15/x
  3. Step 3: Cross multiply
    137.97x = 205.81 × 128.15
  4. Step 4: Simplify right side
    137.97x = 26,373.52
  5. Step 5: Solve for x
    x = 26,373.52/137.97
  6. Step 6: Final answer
    x = 191.16

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.