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Finding the Fourth Proportional to 221.72, 330.53 and 218.21

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Solution

The fourth proportional to 221.72, 330.53 and 218.21 is: 325.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.72 : 330.53 = 218.21 : x
  2. Step 2: Convert to fraction form
    221.72/330.53 = 218.21/x
  3. Step 3: Cross multiply
    221.72x = 330.53 × 218.21
  4. Step 4: Simplify right side
    221.72x = 72,124.95
  5. Step 5: Solve for x
    x = 72,124.95/221.72
  6. Step 6: Final answer
    x = 325.30

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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.