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Finding the Fourth Proportional to 221.43, 330.78 and 209.82

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Solution

The fourth proportional to 221.43, 330.78 and 209.82 is: 313.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.43 : 330.78 = 209.82 : x
  2. Step 2: Convert to fraction form
    221.43/330.78 = 209.82/x
  3. Step 3: Cross multiply
    221.43x = 330.78 × 209.82
  4. Step 4: Simplify right side
    221.43x = 69,403.50
  5. Step 5: Solve for x
    x = 69,403.50/221.43
  6. Step 6: Final answer
    x = 313.43

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.