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Finding the Fourth Proportional to 286.20, 394.80 and 198.72

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Solution

The fourth proportional to 286.20, 394.80 and 198.72 is: 274.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.20 : 394.80 = 198.72 : x
  2. Step 2: Convert to fraction form
    286.20/394.80 = 198.72/x
  3. Step 3: Cross multiply
    286.20x = 394.80 × 198.72
  4. Step 4: Simplify right side
    286.20x = 78,454.66
  5. Step 5: Solve for x
    x = 78,454.66/286.20
  6. Step 6: Final answer
    x = 274.13

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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.