Renee and John have a joint checking account. Their balance at the beginning of September was $6,238.67. During the month they made deposits totaling d dollars, wrote checks totaling $1,459.98, paid a maintenance fee of z dollars, and earned b dollars in interest on the account. Write a simplified algebraic expression that represents the balance at the end of the month

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.