Average talk time between charges of a cell phone is 4 hours. Assume talk time is normally distributed with a standard deviation of 0.8 hour. Show your work.

1.What is the probability that talk time between charges for a randomly selected cell phone is below 3.5 hours?

2.What is the probability that talk time between charges for a randomly selected cell phone is above 4.3 hours?

3.What is the probability that talk time between charges for a randomly selected cell phone is between 3.4 hours and 4.1 hours?

4.The bottom 8% of the distribution are considered defective. What is the highest talk time that would categorize a cell phone to be defective?