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Finding the Fourth Proportional to 280.91, 387.89 and 198.20

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Solution

The fourth proportional to 280.91, 387.89 and 198.20 is: 273.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.91 : 387.89 = 198.20 : x
  2. Step 2: Convert to fraction form
    280.91/387.89 = 198.20/x
  3. Step 3: Cross multiply
    280.91x = 387.89 × 198.20
  4. Step 4: Simplify right side
    280.91x = 76,879.80
  5. Step 5: Solve for x
    x = 76,879.80/280.91
  6. Step 6: Final answer
    x = 273.68

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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.