The test scores of 6 algebra students are: 65,82,75,95,84, 70 Find the population standard deviation of these test scores

given expression is

we have radical  

we need to select an option that has same radical

(a)  

this expression has cube root instead of square root . so it is not a like radical.

(b)

y is included inside the radical. so it is not a like radical.

(c)

this expression has cube root instead of square root . so it is not a like radical.

(d)

5 is inside the radical square root. so it is   a like radical.