Explanation:
a. mean= sum of all observations/total number of observations
=149+111+171+166+152+129+162+144/8
=1184/8
=148
b. median= middle value when arranged in ascending order
= 111 129 144 149 152 162 166 171
middle values= 149 and 152
so median = 149+152/2= 301/2=150.5