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Finding the Fourth Proportional to 221.40, 330.24 and 212.76

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Solution

The fourth proportional to 221.40, 330.24 and 212.76 is: 317.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.40 : 330.24 = 212.76 : x
  2. Step 2: Convert to fraction form
    221.40/330.24 = 212.76/x
  3. Step 3: Cross multiply
    221.40x = 330.24 × 212.76
  4. Step 4: Simplify right side
    221.40x = 70,262.66
  5. Step 5: Solve for x
    x = 70,262.66/221.40
  6. Step 6: Final answer
    x = 317.36

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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.