The function representing the percent of group H in the population is given to be:
![H(x)=0.305x+9.5](https://img.qammunity.org/2023/formulas/mathematics/college/uockzt860qkcudkgshrq721agd3g71hfs8.png)
The number of years after 1990 when the population percentage of group H will be 15.6% can be calculated as follows:
![\begin{gathered} H(x)=15.6 \\ \therefore \\ 15.6=0.305x+9.5 \\ 0.305x=15.6-9.5=6.1 \\ x=(6.1)/(0.305) \\ x=20 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/8jcpi23tn4l4ek2074r4ypbafqpotxc6nt.png)
Therefore, the year will be:
![\Rightarrow1990+20=2010](https://img.qammunity.org/2023/formulas/mathematics/college/zqdzml1q0t8530sjsw68ajph6cqi3f0qxj.png)
What this means is that from 2010 and beyond, the population percentage will be 15.6% or more.
Hence, the population percentage will be at least 15.6% in the year 2010 and after.