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Finding the Fourth Proportional to 311.86, 467.88 and 285.40

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Solution

The fourth proportional to 311.86, 467.88 and 285.40 is: 428.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.86 : 467.88 = 285.40 : x
  2. Step 2: Convert to fraction form
    311.86/467.88 = 285.40/x
  3. Step 3: Cross multiply
    311.86x = 467.88 × 285.40
  4. Step 4: Simplify right side
    311.86x = 133,532.95
  5. Step 5: Solve for x
    x = 133,532.95/311.86
  6. Step 6: Final answer
    x = 428.18

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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.