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Finding the Fourth Proportional to 378.46, 522.25 and 221.11

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Solution

The fourth proportional to 378.46, 522.25 and 221.11 is: 305.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.46 : 522.25 = 221.11 : x
  2. Step 2: Convert to fraction form
    378.46/522.25 = 221.11/x
  3. Step 3: Cross multiply
    378.46x = 522.25 × 221.11
  4. Step 4: Simplify right side
    378.46x = 115,475.78
  5. Step 5: Solve for x
    x = 115,475.78/378.46
  6. Step 6: Final answer
    x = 305.12

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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.