The probability of a randomly selected deer being undernourished is
[tex]P(X<46)=P\left(\dfrac{X-55}{6.2}<\dfrac{46-55}{6.2}\right)\approx P(X<-1.45)\approx0.0733[/tex]
Out of 2100 does, you should expect about [tex]0.0733\cdot2100\approx154[/tex] does to be undernourished.