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Finding the Fourth Proportional to 392.22, 540.81 and 318.31

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Solution

The fourth proportional to 392.22, 540.81 and 318.31 is: 438.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.22 : 540.81 = 318.31 : x
  2. Step 2: Convert to fraction form
    392.22/540.81 = 318.31/x
  3. Step 3: Cross multiply
    392.22x = 540.81 × 318.31
  4. Step 4: Simplify right side
    392.22x = 172,143.88
  5. Step 5: Solve for x
    x = 172,143.88/392.22
  6. Step 6: Final answer
    x = 438.90

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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.