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Finding the Fourth Proportional to 286.28, 428.85 and 221.05

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Solution

The fourth proportional to 286.28, 428.85 and 221.05 is: 331.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.28 : 428.85 = 221.05 : x
  2. Step 2: Convert to fraction form
    286.28/428.85 = 221.05/x
  3. Step 3: Cross multiply
    286.28x = 428.85 × 221.05
  4. Step 4: Simplify right side
    286.28x = 94,797.29
  5. Step 5: Solve for x
    x = 94,797.29/286.28
  6. Step 6: Final answer
    x = 331.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.