In the 4 × 100 Relay Event,each of Four Runners

Multiple Choice

In the 4 × 100 relay event,each of four runners runs 100 metres.A university team is preparing for a competition.The means and standard deviations of the times (in seconds) of their four runners are as shown in the table:
What are the mean and standard deviation of the relay team's total time in this event? Assume that the runners' performances are independent.

A) μ = 48.3 sec,σ = 12.64 sec
B) μ = 48.3 sec,σ = 0.045 sec
C) μ = 24.15 sec,σ = 0.21 sec
D) μ = 48.3 sec,σ = 0.21 sec
E) μ = 24.15 sec,σ = 12.64 sec