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Finding the Fourth Proportional to 128.38, 191.54 and 108.14

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Solution

The fourth proportional to 128.38, 191.54 and 108.14 is: 161.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.38 : 191.54 = 108.14 : x
  2. Step 2: Convert to fraction form
    128.38/191.54 = 108.14/x
  3. Step 3: Cross multiply
    128.38x = 191.54 × 108.14
  4. Step 4: Simplify right side
    128.38x = 20,713.14
  5. Step 5: Solve for x
    x = 20,713.14/128.38
  6. Step 6: Final answer
    x = 161.34

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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.