Consider a three$-$node open Jackson Network as described below. The external $($Poisson process$)$ arrival rate at node $1$ is $25$ per hour and there are no external arrivals to other nodes. There are two servers at each node. The mean $($exponentially distributed$)$ service time at node $1$ is $3$ minutes, at node $2$ it is $2$ minutes, and at node $3$ it is $150$ seconds. After completing the service at node $1,$ all the customers move to node $2$ for service and then to node $3$ for further service. After completing the service at node $3,$ the probability of return to the first node $0\mathrm{.}30$ and the probability of exiting the network is $0\mathrm{.}70.$ Then, the total mean flow rate to node $2$ equals