The lifetime of a certain type of battery is normally dis- tributed with mean value 10 hours and standard deviation 1 hour. there are four batteries in a package. what life- time value is such that the total lifetime of all batteries in a package exceeds that value for only 5% of all packages?

The random variable x represents the number of phone calls an author receives in a day, and it has a poisson distribution with a mean of 8.7 calls. what are the possible values of x

Polygon abcd is a parallelogram, and m? abc = 127°. the length of is 10 units, and the length of is 5 units. the perimeter of the parallelogram is units, and m? bcd is °

An oil exploration company currently has two active projects, one in asia and the other in europe. let a be the event that the asian project is successful and b be the event that the european project is successful. suppose that a and b are independent events with p(a) = 0.2 and p(b) = 0.8. (a) if the asian project is not successful, what is the probability that the european project is also not successful? (b) what is the probability that at least one of the two projects will be successful? (c) given that at least one of the two projects is successful, what is the probability that only the asian project is successful? (round your answer to three decimal places.)