Simplify the following : √0.0081
A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The data obtained for 30 days is as follows:0.030.080.080.090.040.170.160.050.020.060.180.200.110.080.120.130.220.070.080.010.100.060.090.180.110.070.050.070.010.04 The concentration of sulphur dioxide was more than 0.11 parts per million for 8 days.