Boys Girls
Zoo 15 8
Museum 10 12

Mr. White collected data from his eighth grade class on whether they prefer the zoo or the museum. Based on the data collected, if the eighth grade has 90 girls and 78 boys, which statement is true?
A) 31 boys will choose the zoo
B) 36 girls will choose the zoo
C) 40 girls will choose the zoo
D) 47 boys will choose the museum

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?