From the normal distribution curve:

The area from $1{,}000$ to $1{,}100$ is $34\%$.

The area from $800$ to $900$ is $2\%$.

By symmetry, the area from $1{,}100$ to $1{,}200$ equals the area from $800$ to $900$ subtracted from $50\% - 34\%$:

$P(1{,}100 < X < 1{,}200) \approx 14\%$