Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to manufacture a metal clamp
involves the drilling of three holes. In a sample of 81 clamps, the mean time to
complete this step was 42.8 seconds. Assume that the population standard deviation
is 8 seconds. What is the lower bound of the 98% confidence interval?
Round your answer to one decimal place (for example: 41.9).

Ill mark the brainliest if you me with the these three questions 7,8,9

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.

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