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Finding the Fourth Proportional to 378.97, 522.92 and 221.56

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Solution

The fourth proportional to 378.97, 522.92 and 221.56 is: 305.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.97 : 522.92 = 221.56 : x
  2. Step 2: Convert to fraction form
    378.97/522.92 = 221.56/x
  3. Step 3: Cross multiply
    378.97x = 522.92 × 221.56
  4. Step 4: Simplify right side
    378.97x = 115,857.40
  5. Step 5: Solve for x
    x = 115,857.40/378.97
  6. Step 6: Final answer
    x = 305.72

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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.