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Finding the Fourth Proportional to 408.12, 612.32 and 213.18

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Solution

The fourth proportional to 408.12, 612.32 and 213.18 is: 319.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.12 : 612.32 = 213.18 : x
  2. Step 2: Convert to fraction form
    408.12/612.32 = 213.18/x
  3. Step 3: Cross multiply
    408.12x = 612.32 × 213.18
  4. Step 4: Simplify right side
    408.12x = 130,534.38
  5. Step 5: Solve for x
    x = 130,534.38/408.12
  6. Step 6: Final answer
    x = 319.84

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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.