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Finding the Fourth Proportional to 215.82, 321.89 and 212.18

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Solution

The fourth proportional to 215.82, 321.89 and 212.18 is: 316.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.82 : 321.89 = 212.18 : x
  2. Step 2: Convert to fraction form
    215.82/321.89 = 212.18/x
  3. Step 3: Cross multiply
    215.82x = 321.89 × 212.18
  4. Step 4: Simplify right side
    215.82x = 68,295.95
  5. Step 5: Solve for x
    x = 68,295.95/215.82
  6. Step 6: Final answer
    x = 316.45

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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.