Keegan and jeff did some research and found that there are approximately 7,492,000,000,000,000,000 grains of sand on earth. jeff says that this is about 7x10 to the 15th power grains of sand. keegan says this is about 7x10 to the 18th power grains of sand. a. how might jeff have determined his estimate? how might keegan have determined his estimate?
b. who’s estimate, jeff or keegan’s, is more logical, explain

help me pls :’(

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.