Physics
posted by Lisa .
a plane is flying due north at 155 mi/h and encounters a wind from the west at 45m/h. what is the plane's new velocity with respect to the ground in standard position.
answer is 128 mi/h at 239.4. how do i get to this answer.

a plane is flying southwest at 155 mi/h and encounters a wind from the west at 45m/h. what is the plane's new velocity with respect to the ground in standard position.
answer is 128 mi/h at 239.4. how do i get to this answer. 
I do not agree with that answer. You should add 155 N and 45 W as vectors.
I get a ground speed of 161.4 mph, with a direction 16.2 degrees West of North.