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Finding the Fourth Proportional to 318.31, 439.38 and 308.05

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Solution

The fourth proportional to 318.31, 439.38 and 308.05 is: 425.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.31 : 439.38 = 308.05 : x
  2. Step 2: Convert to fraction form
    318.31/439.38 = 308.05/x
  3. Step 3: Cross multiply
    318.31x = 439.38 × 308.05
  4. Step 4: Simplify right side
    318.31x = 135,351.01
  5. Step 5: Solve for x
    x = 135,351.01/318.31
  6. Step 6: Final answer
    x = 425.22

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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.