Internet rates for two companies are shown in the table. After how many months of service is the total cost the same no matter which company is used? What is this total
cost?
Intemet Service Provide
Charges

Tyson's Ethernet $100 activation fee plus $20 per month

Darriana's DSL
$30 per month

A 10 months, $300

B 20 months, $600

C 30 months, $700

D 2 months, $60

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?