The length of the normal drawn at \( t = \frac{\pi}{4} \) on the curve \( x = 2(\cos 2t + t \sin 2t) \), \( y = 4(\sin 2t + t \cos 2t) \) is:
When \( |x| < 2 \), the coefficient of \( x^2 \) in the power series expansion of
\[ \frac{x}{(x-2)(x-3)} \]
is:
The mean deviation about the mean for the following data is: