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Finding the Fourth Proportional to 198.20, 273.64 and 128.30

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Solution

The fourth proportional to 198.20, 273.64 and 128.30 is: 177.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.20 : 273.64 = 128.30 : x
  2. Step 2: Convert to fraction form
    198.20/273.64 = 128.30/x
  3. Step 3: Cross multiply
    198.20x = 273.64 × 128.30
  4. Step 4: Simplify right side
    198.20x = 35,108.01
  5. Step 5: Solve for x
    x = 35,108.01/198.20
  6. Step 6: Final answer
    x = 177.13

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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.