The biology department at a large university reports that historically grades in their introductory biology course have been distributed as follows: 15% A’s, 30% B’s, 40% C’s, 10% D’s and 5% Fs. A random sample of grades in the last semester were distributed as follows: (chart attached)

Test an appropriate hypothesis to decide if the professor’s most recent grade distribution watches the historical distribution. Give statistical evidence to support your claim.

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?

John kept track of how many baskets were made in a basketball game. after 4 minutes, 5 baskets were made. how many baskets were made between 9 and 10 minutes? a. 0 b. 1 c. 2 d. 3

Aband wants to create a cd of their last concert. to creat the cds, the cost will be $350 advertisement fee plus $3 per cd.write an inequality that represents how many cds they can buy with a maximum of $1225.solve the inequality