Answer: z equals 0.60 minus 0.72 all over the square root of the quantity 0.72 times 0.28 over 80
Explanation:
let p be the population proportion of students complete their homework on a daily basis.
As per given , we have
p= 0.72
sample size : n= 80
Sample proportion :

Test statistic for proportion:

i.e.

i.e.

That is , z equals 0.60 minus 0.72 all over the square root of the quantity 0.72 times 0.28 over 80