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: $$\begin{array} { c | c | c } \text { Runner } & \text { Mean } & \text { SD } \\\hline 1 & 12.19 & 0.12 \\2 & 12.37 & 0.14 \\3 & 12.01 & 0.08 \\4 & 11.73 & 0.07\end{array}$$ 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) ? = 48.3 sec,? = 12.64 sec
B) ? = 48.3 sec,? = 0.045 sec
C) ? = 24.15 sec,? = 0.21 sec
D) ? = 48.3 sec,? = 0.21 sec
E) ? = 24.15 sec,? = 12.64 sec