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Finding the Fourth Proportional to 391.38, 539.83 and 378.51

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Solution

The fourth proportional to 391.38, 539.83 and 378.51 is: 522.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.38 : 539.83 = 378.51 : x
  2. Step 2: Convert to fraction form
    391.38/539.83 = 378.51/x
  3. Step 3: Cross multiply
    391.38x = 539.83 × 378.51
  4. Step 4: Simplify right side
    391.38x = 204,327.41
  5. Step 5: Solve for x
    x = 204,327.41/391.38
  6. Step 6: Final answer
    x = 522.08

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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.