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Finding the Fourth Proportional to 311.85, 428.54 and 297.57

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Solution

The fourth proportional to 311.85, 428.54 and 297.57 is: 408.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.85 : 428.54 = 297.57 : x
  2. Step 2: Convert to fraction form
    311.85/428.54 = 297.57/x
  3. Step 3: Cross multiply
    311.85x = 428.54 × 297.57
  4. Step 4: Simplify right side
    311.85x = 127,522.44
  5. Step 5: Solve for x
    x = 127,522.44/311.85
  6. Step 6: Final answer
    x = 408.92

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.