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Finding the Fourth Proportional to 128.09, 192.20 and 97.85

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Solution

The fourth proportional to 128.09, 192.20 and 97.85 is: 146.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.09 : 192.20 = 97.85 : x
  2. Step 2: Convert to fraction form
    128.09/192.20 = 97.85/x
  3. Step 3: Cross multiply
    128.09x = 192.20 × 97.85
  4. Step 4: Simplify right side
    128.09x = 18,805.32
  5. Step 5: Solve for x
    x = 18,805.32/128.09
  6. Step 6: Final answer
    x = 146.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.