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Finding the Fourth Proportional to 221.78, 330.06 and 215.30

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Solution

The fourth proportional to 221.78, 330.06 and 215.30 is: 320.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.78 : 330.06 = 215.30 : x
  2. Step 2: Convert to fraction form
    221.78/330.06 = 215.30/x
  3. Step 3: Cross multiply
    221.78x = 330.06 × 215.30
  4. Step 4: Simplify right side
    221.78x = 71,060.84
  5. Step 5: Solve for x
    x = 71,060.84/221.78
  6. Step 6: Final answer
    x = 320.41

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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.