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Finding the Fourth Proportional to 128.66, 192.04 and 105.57

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Solution

The fourth proportional to 128.66, 192.04 and 105.57 is: 157.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.66 : 192.04 = 105.57 : x
  2. Step 2: Convert to fraction form
    128.66/192.04 = 105.57/x
  3. Step 3: Cross multiply
    128.66x = 192.04 × 105.57
  4. Step 4: Simplify right side
    128.66x = 20,273.40
  5. Step 5: Solve for x
    x = 20,273.40/128.66
  6. Step 6: Final answer
    x = 157.58

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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.