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Finding the Fourth Proportional to 408.26, 612.40 and 215.66

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Solution

The fourth proportional to 408.26, 612.40 and 215.66 is: 323.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.26 : 612.40 = 215.66 : x
  2. Step 2: Convert to fraction form
    408.26/612.40 = 215.66/x
  3. Step 3: Cross multiply
    408.26x = 612.40 × 215.66
  4. Step 4: Simplify right side
    408.26x = 132,070.18
  5. Step 5: Solve for x
    x = 132,070.18/408.26
  6. Step 6: Final answer
    x = 323.50

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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.