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Finding the Fourth Proportional to 389.70, 537.77 and 221.64

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Solution

The fourth proportional to 389.70, 537.77 and 221.64 is: 305.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.70 : 537.77 = 221.64 : x
  2. Step 2: Convert to fraction form
    389.70/537.77 = 221.64/x
  3. Step 3: Cross multiply
    389.70x = 537.77 × 221.64
  4. Step 4: Simplify right side
    389.70x = 119,190.23
  5. Step 5: Solve for x
    x = 119,190.23/389.70
  6. Step 6: Final answer
    x = 305.85

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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.