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Finding the Fourth Proportional to 392.49, 542.04 and 339.78

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Solution

The fourth proportional to 392.49, 542.04 and 339.78 is: 469.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.49 : 542.04 = 339.78 : x
  2. Step 2: Convert to fraction form
    392.49/542.04 = 339.78/x
  3. Step 3: Cross multiply
    392.49x = 542.04 × 339.78
  4. Step 4: Simplify right side
    392.49x = 184,174.35
  5. Step 5: Solve for x
    x = 184,174.35/392.49
  6. Step 6: Final answer
    x = 469.25

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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.