Round 51.478 to nearest tenth

Which graph represents an even function?

1. 2. ∠b and ∠y are right angles. 3.? 4.? which two statements are missing in steps 3 and 4? ∠x ≅ ∠c △abc ~ △zyx by the sas similarity theorem. ∠b ≅ ∠y △abc ~ △zyx by the sas similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem.

Is the response to the survey question "did you smoke in the last week question mark "response to the survey question "did you smoke in the last week? " a discrete random variable, a continuous random variable, or not a random variable?