How many lines should we include in our sample if we want to estimate the average length of the lines drawn by our class with 95% confidence of being within 0.2 inches of the true average? Assume the standard deviation of line lengths is 0.3 inches. z * = _______________ s = ___________ ME = ___________ What if you want to be 90% confident? ( ) 2 = ( ) 2 = Round UP to get n = ___________ Notice that n is smaller since we can be less sure