The postmaster of a small western town receives a certain number of complaints each day about mail delivery.

a$.$Determine two$-$sigma control limits using the above data. $($Round your intermediate calculations to $4$ decimal places

and final answers to $3$ decimal places. Leave no cells blank $-$ be certain to enter $"0"$ wherever required. Round up any negative

control limit value to zero.$)$

My answers were wrong, so help would be greatly appreciated.