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Finding the Fourth Proportional to 391.38, 539.96 and 318.18

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Solution

The fourth proportional to 391.38, 539.96 and 318.18 is: 438.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.38 : 539.96 = 318.18 : x
  2. Step 2: Convert to fraction form
    391.38/539.96 = 318.18/x
  3. Step 3: Cross multiply
    391.38x = 539.96 × 318.18
  4. Step 4: Simplify right side
    391.38x = 171,804.47
  5. Step 5: Solve for x
    x = 171,804.47/391.38
  6. Step 6: Final answer
    x = 438.97

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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.