For δabc, ∠a = x + 30, ∠b = 2x - 4, and ∠c = 4x. if δabc undergoes a dilation by a scale factor of 1/2 to create δa'b'c' with ∠a' = 2x + 8, ∠b' = x + 18, and ∠c' = 5x - 22, which confirms that δabc∼δa'b'c by the aa criterion?

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.