customers arrive at a counter in a store according to a poisson distribution at an average of 7 per hr. it takes approx 10 min to serve each customer, find the mean and var of the total service time for customers arriving during a 1hr period.

if it takes 10mins and there are 7customers in a 1hr period, wont the total service time = E(X) = 7 x 10 and the var(X) =49 x 10?

i think im confused..can someone help me?