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Finding the Fourth Proportional to 378.93, 523.05 and 221.61

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Solution

The fourth proportional to 378.93, 523.05 and 221.61 is: 305.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.93 : 523.05 = 221.61 : x
  2. Step 2: Convert to fraction form
    378.93/523.05 = 221.61/x
  3. Step 3: Cross multiply
    378.93x = 523.05 × 221.61
  4. Step 4: Simplify right side
    378.93x = 115,913.11
  5. Step 5: Solve for x
    x = 115,913.11/378.93
  6. Step 6: Final answer
    x = 305.90

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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.