Yes, it was a typo. The point should be (3, -1, 4) , and not (3, 1, -4).
For the the line, x= 3+ 3t, y= 1- 2t, z= 4 , should 1 or 4, in y and z respectively, be negative? (since the point, at the time you typed your response, could have been (3, -1, 4) or (3, 1, -4).
Thank you for your...