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Finding the Fourth Proportional to 128.86, 192.05 and 122.38

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Solution

The fourth proportional to 128.86, 192.05 and 122.38 is: 182.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.86 : 192.05 = 122.38 : x
  2. Step 2: Convert to fraction form
    128.86/192.05 = 122.38/x
  3. Step 3: Cross multiply
    128.86x = 192.05 × 122.38
  4. Step 4: Simplify right side
    128.86x = 23,502.47
  5. Step 5: Solve for x
    x = 23,502.47/128.86
  6. Step 6: Final answer
    x = 182.39

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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.