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Finding the Fourth Proportional to 128.89, 192.13 and 122.05

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Solution

The fourth proportional to 128.89, 192.13 and 122.05 is: 181.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.89 : 192.13 = 122.05 : x
  2. Step 2: Convert to fraction form
    128.89/192.13 = 122.05/x
  3. Step 3: Cross multiply
    128.89x = 192.13 × 122.05
  4. Step 4: Simplify right side
    128.89x = 23,449.47
  5. Step 5: Solve for x
    x = 23,449.47/128.89
  6. Step 6: Final answer
    x = 181.93

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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.