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Finding the Fourth Proportional to 392.55, 587.89 and 218.79

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Solution

The fourth proportional to 392.55, 587.89 and 218.79 is: 327.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.55 : 587.89 = 218.79 : x
  2. Step 2: Convert to fraction form
    392.55/587.89 = 218.79/x
  3. Step 3: Cross multiply
    392.55x = 587.89 × 218.79
  4. Step 4: Simplify right side
    392.55x = 128,620.42
  5. Step 5: Solve for x
    x = 128,620.42/392.55
  6. Step 6: Final answer
    x = 327.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.