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Finding the Fourth Proportional to 215.52, 321.09 and 208.68

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Solution

The fourth proportional to 215.52, 321.09 and 208.68 is: 310.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.52 : 321.09 = 208.68 : x
  2. Step 2: Convert to fraction form
    215.52/321.09 = 208.68/x
  3. Step 3: Cross multiply
    215.52x = 321.09 × 208.68
  4. Step 4: Simplify right side
    215.52x = 67,005.06
  5. Step 5: Solve for x
    x = 67,005.06/215.52
  6. Step 6: Final answer
    x = 310.90

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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.