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Finding the Fourth Proportional to 128.97, 178.20 and 104.37

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Solution

The fourth proportional to 128.97, 178.20 and 104.37 is: 144.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.97 : 178.20 = 104.37 : x
  2. Step 2: Convert to fraction form
    128.97/178.20 = 104.37/x
  3. Step 3: Cross multiply
    128.97x = 178.20 × 104.37
  4. Step 4: Simplify right side
    128.97x = 18,598.07
  5. Step 5: Solve for x
    x = 18,598.07/128.97
  6. Step 6: Final answer
    x = 144.20

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.