A botany student measured the lengths of a sample of leaves to the nearest centimeter. The data is shown in the frequency distribution below. Use the data to approximate the following to the nearest tenth of a centimeter. Length Frequency midpoint midpoint x frequency [midpoint-mean)2x frequency 4 l l l l 6-11 7 l l l l 12-17 12 ' ' ' ' 18-23 17 ' ' ' ' sum= sum= ' ' sum= ' ' Mean= ' \\.I\"ariance= ' ' Standard Deviation=