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Finding the Fourth Proportional to 217.61, 326.30 and 80.55

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Solution

The fourth proportional to 217.61, 326.30 and 80.55 is: 120.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.61 : 326.30 = 80.55 : x
  2. Step 2: Convert to fraction form
    217.61/326.30 = 80.55/x
  3. Step 3: Cross multiply
    217.61x = 326.30 × 80.55
  4. Step 4: Simplify right side
    217.61x = 26,283.06
  5. Step 5: Solve for x
    x = 26,283.06/217.61
  6. Step 6: Final answer
    x = 120.78

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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.