A linear function can be used to estimate the decrease in snowfall measured since 1920. The decrease in the annual snowfall has been on average 0.24 inches per year. Let x represent the number of years since 1920, when the measurements began, and let y represent the annual snowfall. The initial measurement in 1920 was 48.6 inches. Using the average change and initial measurement, which is the best estimate of the annual snowfall in the 78th year after records were kept? Round to the nearest hundredth. 15.84 inches
27.72 inches
29.88 inches
67.32 inches

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?