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Finding the Fourth Proportional to 128.25, 191.43 and 119.61

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Solution

The fourth proportional to 128.25, 191.43 and 119.61 is: 178.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.25 : 191.43 = 119.61 : x
  2. Step 2: Convert to fraction form
    128.25/191.43 = 119.61/x
  3. Step 3: Cross multiply
    128.25x = 191.43 × 119.61
  4. Step 4: Simplify right side
    128.25x = 22,896.94
  5. Step 5: Solve for x
    x = 22,896.94/128.25
  6. Step 6: Final answer
    x = 178.53

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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.