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Finding the Fourth Proportional to 215.75, 321.34 and 209.98

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Solution

The fourth proportional to 215.75, 321.34 and 209.98 is: 312.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.75 : 321.34 = 209.98 : x
  2. Step 2: Convert to fraction form
    215.75/321.34 = 209.98/x
  3. Step 3: Cross multiply
    215.75x = 321.34 × 209.98
  4. Step 4: Simplify right side
    215.75x = 67,474.97
  5. Step 5: Solve for x
    x = 67,474.97/215.75
  6. Step 6: Final answer
    x = 312.75

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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.