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Finding the Fourth Proportional to 392.31, 540.41 and 287.12

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Solution

The fourth proportional to 392.31, 540.41 and 287.12 is: 395.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.31 : 540.41 = 287.12 : x
  2. Step 2: Convert to fraction form
    392.31/540.41 = 287.12/x
  3. Step 3: Cross multiply
    392.31x = 540.41 × 287.12
  4. Step 4: Simplify right side
    392.31x = 155,162.52
  5. Step 5: Solve for x
    x = 155,162.52/392.31
  6. Step 6: Final answer
    x = 395.51

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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.