One drive-through car wash facility offers three different types of washes: basic, deluxe, and supreme. The manager of the car wash facility tallies customer selections over three days.
Type of Car Wash
Basic
Deluxe
Supreme
Total
Friday
15
43
19
77
Day
Saturday
27
52
22
101
Sunday
23
45
19
87
Total
65
140
60
265
Given that a customer got their car washed on Friday, what is the probability that the customer selected the deluxe car
wash?
16.2%
30.7%
52.8%

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?