The [tex]z[/tex]-score for a height of 16.4 feet is
[tex]z=\dfrac{16.4-14.2}{2.15}\approx1.023[/tex]
So
[tex]P(\text{height}>16.4\,\mathrm{ft})=P(Z>1.023)=1-F_Z(1.023)\approx0.153[/tex]
where [tex]F_Z(z)=P(Z\le z)[/tex] is the cumulative distribution function for the standard normal distribution.