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Finding the Fourth Proportional to 221.40, 331.21 and 191.29

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Solution

The fourth proportional to 221.40, 331.21 and 191.29 is: 286.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.40 : 331.21 = 191.29 : x
  2. Step 2: Convert to fraction form
    221.40/331.21 = 191.29/x
  3. Step 3: Cross multiply
    221.40x = 331.21 × 191.29
  4. Step 4: Simplify right side
    221.40x = 63,357.16
  5. Step 5: Solve for x
    x = 63,357.16/221.40
  6. Step 6: Final answer
    x = 286.17

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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.