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Finding the Fourth Proportional to 378.45, 522.28 and 221.06

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Solution

The fourth proportional to 378.45, 522.28 and 221.06 is: 305.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.45 : 522.28 = 221.06 : x
  2. Step 2: Convert to fraction form
    378.45/522.28 = 221.06/x
  3. Step 3: Cross multiply
    378.45x = 522.28 × 221.06
  4. Step 4: Simplify right side
    378.45x = 115,454.11
  5. Step 5: Solve for x
    x = 115,454.11/378.45
  6. Step 6: Final answer
    x = 305.07

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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.