In 2006, there were approximately 233 million cell phone subscribers in the United States. During the next 4 years, the number of cell phone subscribers increased by about 6% each year.
a. Write an exponential growth model giving the number of cell phone subscribers y (in millions) t years after 2006.
Estimate the number of cell phone subscribers in 2008. Round your answer to the nearest tenth.
3
about_million subscribers
b. Estimate the year when the number of cell phone subscribers was about 278 million Round your answer to the nearest whole year.
The number of subscribers was about 278 million in
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work

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?