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Finding the Fourth Proportional to 221.09, 331.51 and 84.15

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Solution

The fourth proportional to 221.09, 331.51 and 84.15 is: 126.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.09 : 331.51 = 84.15 : x
  2. Step 2: Convert to fraction form
    221.09/331.51 = 84.15/x
  3. Step 3: Cross multiply
    221.09x = 331.51 × 84.15
  4. Step 4: Simplify right side
    221.09x = 27,895.74
  5. Step 5: Solve for x
    x = 27,895.74/221.09
  6. Step 6: Final answer
    x = 126.17

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.