Which sequence is geometric and has 1/4' as its fifth term and 1/2' as the common ratio?
O A..., 1,' 1/2, 1/4, 1/8"...
B..., 1/4, 1/2,' '1, 2, ...
OC..., 1872, -1/36','1/18", 19 ...
D, 8,' '4,' '2' 1,' ...

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?