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Finding the Fourth Proportional to 217.55, 326.30 and 80.61

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Solution

The fourth proportional to 217.55, 326.30 and 80.61 is: 120.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.55 : 326.30 = 80.61 : x
  2. Step 2: Convert to fraction form
    217.55/326.30 = 80.61/x
  3. Step 3: Cross multiply
    217.55x = 326.30 × 80.61
  4. Step 4: Simplify right side
    217.55x = 26,303.24
  5. Step 5: Solve for x
    x = 26,303.24/217.55
  6. Step 6: Final answer
    x = 120.91

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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.