Question 1167660
z=(x-mean)/sd
=(729-853)/100=-1.24
and (1021-853)/100=+1.68
 probability is z between those two values, which is 84.60%

greater than 995 is z>1.42 or probability 7.78%

top 2% is z of 2.05
this would therefore be 205 more than the mean or 1058.

look at 873  z=(873-853)/100/sqrt(41)=20*sqrt(41)/100 or 1.28.  Not less than 873 is z>1.28 which is 0.1003.