A simple pendulum is used to measure g, using the relation T=2piesqrt(l/g), where T is the period, l is the length, and g is the acceleration due to gravity. Twenty measurements of T give a mean of barT=1.82 sec and a standard deviation of .06 sec. Ten measurements of l give a mean of barl=.823 m and a standard deviation of 0.014. What is the standard deviation of the mean, barg, for the calculated value of g?