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Finding the Fourth Proportional to 306.28, 422.74 and 217.90

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Solution

The fourth proportional to 306.28, 422.74 and 217.90 is: 300.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.28 : 422.74 = 217.90 : x
  2. Step 2: Convert to fraction form
    306.28/422.74 = 217.90/x
  3. Step 3: Cross multiply
    306.28x = 422.74 × 217.90
  4. Step 4: Simplify right side
    306.28x = 92,115.05
  5. Step 5: Solve for x
    x = 92,115.05/306.28
  6. Step 6: Final answer
    x = 300.75

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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.