Casey told a secret to two friends and made them promise not to tell anyone. Too bad for Casey, each
of those friends each told 2 more friends, and so on.
If this continues, how many people find out about
Casey's secret in the eighth round?

In order to be invited to tutoring or extension activities a students performance 20 point higher or lower than average for the

There were 25 students who answered to a survey about sports. four-fifths of them like football. how many students like football?

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?