Sarah took the advertising department for a company on a round trip to meet a potential client, including Sarah, a total of 13 took the trip, she was able to purchase coach tickets for 380 dollars and first class tickets for 1210 dollars. She used her total budget for air fare for the trip, which was 11,580 dollars, how many first class tickets did she buy? how many coach tickets did she buy?​

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?