11 + (3)(9)
Step 1: 11 + (9)(3)
Step 2: (11 + 9)(3)
Step 3: 20(3)
Step 4: 60
Analyze the work to find the error.
O In Step 1, the commutative property of
multiplication was not done correctly
O In Step 2, the associative property cannot regroup
addition and multiplication
O In Step 3, the multiplication must be done first
In Step 4, the product is incorrect

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.