Last year, 42,317 students participated in a robotics league. What is the value of the 4 in the number of students who participated in the robotics league? A.
one-tenth times the value of the two in the thousands place
B.
two times the value of the two in the thousands place
C.
ten times the value of the two in the thousands place
D.
twenty times the value of the two in the thousands place

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?