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Finding the Fourth Proportional to 389.89, 538.04 and 221.82

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Solution

The fourth proportional to 389.89, 538.04 and 221.82 is: 306.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.89 : 538.04 = 221.82 : x
  2. Step 2: Convert to fraction form
    389.89/538.04 = 221.82/x
  3. Step 3: Cross multiply
    389.89x = 538.04 × 221.82
  4. Step 4: Simplify right side
    389.89x = 119,348.03
  5. Step 5: Solve for x
    x = 119,348.03/389.89
  6. Step 6: Final answer
    x = 306.11

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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.