The accepted density of copper is 8.96 g/cm3. A lab team measured the density of a copper sample in a lab and calculated a density of 8.40 g/cm3. Part A: Which expression calculates the percent error for the calculated density of copper?
Part B: What is the percent error?
Select two answers: one for Part A and one for Part B.

A: 8.40 / |8.4+8.96| x 100
A: |8.40| / 8.96 x 100
A: |8.40−8.96| / 8.96 x 100
A: |8.40−8.96| / 8.40 x 100
B: 4.84%
B: 6.51%
B: 6.67%
B: 2.33%

What is the ratio for the surface areas of rectangle prisims shown below given that they are similar and that the ratio of their edge lengths is 7: 3

Need on this geometry question. explain how you did it.

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?