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Finding the Fourth Proportional to 408.20, 612.29 and 100.05

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Solution

The fourth proportional to 408.20, 612.29 and 100.05 is: 150.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.20 : 612.29 = 100.05 : x
  2. Step 2: Convert to fraction form
    408.20/612.29 = 100.05/x
  3. Step 3: Cross multiply
    408.20x = 612.29 × 100.05
  4. Step 4: Simplify right side
    408.20x = 61,261.15
  5. Step 5: Solve for x
    x = 61,261.15/408.20
  6. Step 6: Final answer
    x = 150.08

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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.