The mean age of 5 people in a room is 36 years. A person enters the room. The mean age is now 39. What is the age of the person who entered the room?

Your answer is 36.5. Hope this helps!

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.