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Finding the Fourth Proportional to 392.09, 540.41 and 287.15

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Solution

The fourth proportional to 392.09, 540.41 and 287.15 is: 395.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.09 : 540.41 = 287.15 : x
  2. Step 2: Convert to fraction form
    392.09/540.41 = 287.15/x
  3. Step 3: Cross multiply
    392.09x = 540.41 × 287.15
  4. Step 4: Simplify right side
    392.09x = 155,174.59
  5. Step 5: Solve for x
    x = 155,174.59/392.09
  6. Step 6: Final answer
    x = 395.77

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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.