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Finding the Fourth Proportional to 378.92, 522.78 and 221.54

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Solution

The fourth proportional to 378.92, 522.78 and 221.54 is: 305.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.92 : 522.78 = 221.54 : x
  2. Step 2: Convert to fraction form
    378.92/522.78 = 221.54/x
  3. Step 3: Cross multiply
    378.92x = 522.78 × 221.54
  4. Step 4: Simplify right side
    378.92x = 115,814.07
  5. Step 5: Solve for x
    x = 115,814.07/378.92
  6. Step 6: Final answer
    x = 305.65

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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.