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Finding the Fourth Proportional to 217.39, 326.16 and 85.63

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Solution

The fourth proportional to 217.39, 326.16 and 85.63 is: 128.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.39 : 326.16 = 85.63 : x
  2. Step 2: Convert to fraction form
    217.39/326.16 = 85.63/x
  3. Step 3: Cross multiply
    217.39x = 326.16 × 85.63
  4. Step 4: Simplify right side
    217.39x = 27,929.08
  5. Step 5: Solve for x
    x = 27,929.08/217.39
  6. Step 6: Final answer
    x = 128.47

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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.