20 POINTS NUMBER 9 please

Divide. write in the simplest form. 4 1/6 divided by 10

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.

Rewrite so the subject can be y in the formula d=m-y/y+n