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Finding the Fourth Proportional to 391.76, 540.60 and 217.12

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Solution

The fourth proportional to 391.76, 540.60 and 217.12 is: 299.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.76 : 540.60 = 217.12 : x
  2. Step 2: Convert to fraction form
    391.76/540.60 = 217.12/x
  3. Step 3: Cross multiply
    391.76x = 540.60 × 217.12
  4. Step 4: Simplify right side
    391.76x = 117,375.07
  5. Step 5: Solve for x
    x = 117,375.07/391.76
  6. Step 6: Final answer
    x = 299.61

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.