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Finding the Fourth Proportional to 311.37, 428.96 and 217.95

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Solution

The fourth proportional to 311.37, 428.96 and 217.95 is: 300.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.37 : 428.96 = 217.95 : x
  2. Step 2: Convert to fraction form
    311.37/428.96 = 217.95/x
  3. Step 3: Cross multiply
    311.37x = 428.96 × 217.95
  4. Step 4: Simplify right side
    311.37x = 93,491.83
  5. Step 5: Solve for x
    x = 93,491.83/311.37
  6. Step 6: Final answer
    x = 300.26

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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.