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Finding the Fourth Proportional to 640.98, 961.51 and 218.65

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Solution

The fourth proportional to 640.98, 961.51 and 218.65 is: 327.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.98 : 961.51 = 218.65 : x
  2. Step 2: Convert to fraction form
    640.98/961.51 = 218.65/x
  3. Step 3: Cross multiply
    640.98x = 961.51 × 218.65
  4. Step 4: Simplify right side
    640.98x = 210,234.16
  5. Step 5: Solve for x
    x = 210,234.16/640.98
  6. Step 6: Final answer
    x = 327.99

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.