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Finding the Fourth Proportional to 408.86, 612.86 and 311.15

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Solution

The fourth proportional to 408.86, 612.86 and 311.15 is: 466.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.86 : 612.86 = 311.15 : x
  2. Step 2: Convert to fraction form
    408.86/612.86 = 311.15/x
  3. Step 3: Cross multiply
    408.86x = 612.86 × 311.15
  4. Step 4: Simplify right side
    408.86x = 190,691.39
  5. Step 5: Solve for x
    x = 190,691.39/408.86
  6. Step 6: Final answer
    x = 466.40

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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.