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Finding the Fourth Proportional to 391.31, 540.07 and 318.18

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Solution

The fourth proportional to 391.31, 540.07 and 318.18 is: 439.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.31 : 540.07 = 318.18 : x
  2. Step 2: Convert to fraction form
    391.31/540.07 = 318.18/x
  3. Step 3: Cross multiply
    391.31x = 540.07 × 318.18
  4. Step 4: Simplify right side
    391.31x = 171,837.66
  5. Step 5: Solve for x
    x = 171,837.66/391.31
  6. Step 6: Final answer
    x = 439.14

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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.