the complete question in the attached figure
we know that
the root mean square speed, is the square root of the average (mean) of all of the square of the speeds of individual particles in a gas.
step 1
find the square of the speeds of individual particles
2.8²----> 7.84
3.2²---->10.24
5.8²----> 33.64
7.3²----> 53.29
7.4²---> 54.76
average=[7.84+10.24+33.64+53.29+54.76]/5-----> 159.77/5----> 31.954
step 2
find the square root of the average
√31.954=5.65
therefore
the answer isthe option b) 5.7 m/s
