What is the standard deviation of the following data set: 4, 7, 2, 9, 6?
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What is the equation of an ellipse with foci (0, ±5) and major axis length 10?
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What is the resultant vector when a vector of magnitude 25 units at a 45° angle to the x-axis is added to a vector of magnitude 35 units at a 135° angle to the x-axis?