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Finding the Fourth Proportional to 143.97, 198.21 and 128.14

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Solution

The fourth proportional to 143.97, 198.21 and 128.14 is: 176.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.97 : 198.21 = 128.14 : x
  2. Step 2: Convert to fraction form
    143.97/198.21 = 128.14/x
  3. Step 3: Cross multiply
    143.97x = 198.21 × 128.14
  4. Step 4: Simplify right side
    143.97x = 25,398.45
  5. Step 5: Solve for x
    x = 25,398.45/143.97
  6. Step 6: Final answer
    x = 176.42

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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.