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Finding the Fourth Proportional to 389.81, 537.80 and 221.73

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Solution

The fourth proportional to 389.81, 537.80 and 221.73 is: 305.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.81 : 537.80 = 221.73 : x
  2. Step 2: Convert to fraction form
    389.81/537.80 = 221.73/x
  3. Step 3: Cross multiply
    389.81x = 537.80 × 221.73
  4. Step 4: Simplify right side
    389.81x = 119,245.29
  5. Step 5: Solve for x
    x = 119,245.29/389.81
  6. Step 6: Final answer
    x = 305.91

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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.