Question $4$

Suppose our critical path had four activities with the following variances:

Activity A: $2\mathrm{.}56$

Activity B: $7\mathrm{.}34$

Activity C: $0\mathrm{.}65$

Activity D: $2\mathrm{.}00$

What is the project standard deviation?

$12\mathrm{.}55$

$4\mathrm{.}39$

$3\mathrm{.}54$

$7\mathrm{.}34$