A project plan is given below:

(a) Construct a $$PERT$$ network
(b) Find the critical path and estimate the project duration.

The most commonly used criteria for measuring forecast error is

In a forecasting model, at the end of period $$13,$$ the forecasted value for period $$14$$ is $$75.$$ Actual value in the periods $$14$$ to $$16$$ are constant at $$100$$. if the assumed simple exponential smoothing parameter is $$0.5,$$ then the $$MSE$$ at the end of period $$16$$ is

The cost of providing service in a queuing system increases with