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Finding the Fourth Proportional to 392.85, 542.13 and 218.19

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Solution

The fourth proportional to 392.85, 542.13 and 218.19 is: 301.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.85 : 542.13 = 218.19 : x
  2. Step 2: Convert to fraction form
    392.85/542.13 = 218.19/x
  3. Step 3: Cross multiply
    392.85x = 542.13 × 218.19
  4. Step 4: Simplify right side
    392.85x = 118,286.25
  5. Step 5: Solve for x
    x = 118,286.25/392.85
  6. Step 6: Final answer
    x = 301.10

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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.