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Finding the Fourth Proportional to 640.98, 961.66 and 208.18

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Solution

The fourth proportional to 640.98, 961.66 and 208.18 is: 312.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.98 : 961.66 = 208.18 : x
  2. Step 2: Convert to fraction form
    640.98/961.66 = 208.18/x
  3. Step 3: Cross multiply
    640.98x = 961.66 × 208.18
  4. Step 4: Simplify right side
    640.98x = 200,198.38
  5. Step 5: Solve for x
    x = 200,198.38/640.98
  6. Step 6: Final answer
    x = 312.33

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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.