A survey regarding the heights (in cm) of 51 girls of Class X of a school was conducted and the following data was obtained: | Height (in cm) | Number of girls | |----------------|-----------------| | Less than 140 | 4 | | Less than 145 | 11 | | Less than 150 | 29 | | Less than 155 | 40 | | Less than 160 | 46 | | Less than 165 | 51 | Find the median height.