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Finding the Fourth Proportional to 392.87, 542.21 and 243.47

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Solution

The fourth proportional to 392.87, 542.21 and 243.47 is: 336.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.87 : 542.21 = 243.47 : x
  2. Step 2: Convert to fraction form
    392.87/542.21 = 243.47/x
  3. Step 3: Cross multiply
    392.87x = 542.21 × 243.47
  4. Step 4: Simplify right side
    392.87x = 132,007.94
  5. Step 5: Solve for x
    x = 132,007.94/392.87
  6. Step 6: Final answer
    x = 336.01

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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.