Probability for stats ?

Number of combinations of rolling 2 dice
= 6²
= 36

A sum of 2: (1,1)
A sum of 3: (1, 2), (2, 1)
Number of combinations of getting a sum of 2 or 3
= 3

The required probability
= P(get a sum at least 4)
= 1 - P(get a sum of 2 or 3)
= 1 - (3/36)
= 1 - (1/12)
= 11/12
= 0.91666667

P(sum of at least 4) = 33/36 or 11/12 or  0.91666667 answer//

To roll at least 4 is possible, but is not a certainty. Therefore it is not possible to find the probability of doing that every time without knowing how many times there are. If by every time you mean to do so on every roll throughout eternity, an infinite number of trials, then that probability is zero. And no, that is not an approximation. The probability is exactly zero.

Rounded to eight decimal places, that is 0.00000000.