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Finding the Fourth Proportional to 391.75, 540.63 and 217.09

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Solution

The fourth proportional to 391.75, 540.63 and 217.09 is: 299.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.75 : 540.63 = 217.09 : x
  2. Step 2: Convert to fraction form
    391.75/540.63 = 217.09/x
  3. Step 3: Cross multiply
    391.75x = 540.63 × 217.09
  4. Step 4: Simplify right side
    391.75x = 117,365.37
  5. Step 5: Solve for x
    x = 117,365.37/391.75
  6. Step 6: Final answer
    x = 299.59

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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.