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Finding the Fourth Proportional to 408.80, 613.32 and 311.40

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Solution

The fourth proportional to 408.80, 613.32 and 311.40 is: 467.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.80 : 613.32 = 311.40 : x
  2. Step 2: Convert to fraction form
    408.80/613.32 = 311.40/x
  3. Step 3: Cross multiply
    408.80x = 613.32 × 311.40
  4. Step 4: Simplify right side
    408.80x = 190,987.85
  5. Step 5: Solve for x
    x = 190,987.85/408.80
  6. Step 6: Final answer
    x = 467.20

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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.