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Finding the Fourth Proportional to 378.96, 522.93 and 221.61

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Solution

The fourth proportional to 378.96, 522.93 and 221.61 is: 305.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.96 : 522.93 = 221.61 : x
  2. Step 2: Convert to fraction form
    378.96/522.93 = 221.61/x
  3. Step 3: Cross multiply
    378.96x = 522.93 × 221.61
  4. Step 4: Simplify right side
    378.96x = 115,886.52
  5. Step 5: Solve for x
    x = 115,886.52/378.96
  6. Step 6: Final answer
    x = 305.80

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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.