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Finding the Fourth Proportional to 128.54, 178.12 and 126.11

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Solution

The fourth proportional to 128.54, 178.12 and 126.11 is: 174.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.54 : 178.12 = 126.11 : x
  2. Step 2: Convert to fraction form
    128.54/178.12 = 126.11/x
  3. Step 3: Cross multiply
    128.54x = 178.12 × 126.11
  4. Step 4: Simplify right side
    128.54x = 22,461.82
  5. Step 5: Solve for x
    x = 22,461.82/128.54
  6. Step 6: Final answer
    x = 174.75

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.