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Finding the Fourth Proportional to 128.81, 194.19 and 108.66

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Solution

The fourth proportional to 128.81, 194.19 and 108.66 is: 163.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.81 : 194.19 = 108.66 : x
  2. Step 2: Convert to fraction form
    128.81/194.19 = 108.66/x
  3. Step 3: Cross multiply
    128.81x = 194.19 × 108.66
  4. Step 4: Simplify right side
    128.81x = 21,100.69
  5. Step 5: Solve for x
    x = 21,100.69/128.81
  6. Step 6: Final answer
    x = 163.82

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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.