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Finding the Fourth Proportional to 286.91, 396.06 and 221.30

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Solution

The fourth proportional to 286.91, 396.06 and 221.30 is: 305.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.91 : 396.06 = 221.30 : x
  2. Step 2: Convert to fraction form
    286.91/396.06 = 221.30/x
  3. Step 3: Cross multiply
    286.91x = 396.06 × 221.30
  4. Step 4: Simplify right side
    286.91x = 87,648.08
  5. Step 5: Solve for x
    x = 87,648.08/286.91
  6. Step 6: Final answer
    x = 305.49

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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.