The Number of Emergency Calls Received by a Switchboard in an Hour

Multiple Choice

The number of emergency calls received by a switchboard in an hour has an expected value of 0.5 and a standard deviation of 0.7.Find the mean and standard deviation of the number of emergency calls received by the switch board during a workshift lasting 4 hours.Assume that the hours are independent of each other.

A) μ = 2,σ = 11.2
B) μ = 1.00,σ = 2.8
C) μ = 2,σ = 2.8
D) μ = 2,σ = 1.40
E) μ = 1.00,σ = 1.40