Given that, the variable z is inversely proportional to x.
So, we can set up an equation as following:
z * x = k Where k is constant of variation.
Also given that, when x = 5 then z =0.8.
Next step is to plug in these values in the above equation to get the value of k.
So, 0.8 * 5 =k
k = 4
So, the equation become : z* x = 4.
Now we need to find the vaue of z when x=12. Hence,
z * 12 = 4
z = [tex] \frac{4}{12} [/tex] Divided each sides by 12 t isolate z.
z = 0.3 Rounded to tenth.
So, z= 0.3
Hope this helps you !