This is a binomial distribution type problem, where the probability under the question is the sum


     P =       (1)


The number of trials is              8;
The indexes of success trials        k = 2,3,4,5,6,7,8
The probability of success trial     p = 0.28;
                                     q = 1 - p
C(n,k) = n! / (k! * (n-k)!)          are binomial coefficients.


The sum  (1)  is equal to  1 - .     (2)



You may calculate each term in (2) individually and then sum them up.


Or, alternatively, you may use Excel function  BINOM.DIST(1, 8, 0.28, TRUE)  to calculate the cumulative sum value


     = 0.296906.    


In this way, the value of  (2)  is equal to  1 - 0.296906 = 0.703094 (approximately).    ANSWER