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Finding the Fourth Proportional to 311.31, 428.49 and 298.35

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Solution

The fourth proportional to 311.31, 428.49 and 298.35 is: 410.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.31 : 428.49 = 298.35 : x
  2. Step 2: Convert to fraction form
    311.31/428.49 = 298.35/x
  3. Step 3: Cross multiply
    311.31x = 428.49 × 298.35
  4. Step 4: Simplify right side
    311.31x = 127,839.99
  5. Step 5: Solve for x
    x = 127,839.99/311.31
  6. Step 6: Final answer
    x = 410.65

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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.