They are asking you for a graph of height (of the bottom of the spring) with respect to time.
Time in seconds will be the horizontal axis, and height is the vertical axis.
The midline is the bottom of the weight when the spring is at rest. That is 1.6metres above the ground
The mass is pulled down by 1.1 metres - so that is the amplitude.
the wavelength is 1 second (1/2 +1/2)
The way I am looking at it, the spring starts at the bottom of its cycle so this is a reflection of the usual cos graph about the line y=1.6
so the equation is
y=-1.1cos[(2pi/wavelength)x]+1.6
y = -1.1cos(2pi*x)+1.6
![](https://i.gyazo.com/02760006f583a5b9e40ac98f2cd7de6c.png)