The time to failure (in hours) of fans in a personal computer can be modeled by an exponential distribution with . Round your answers to 4 decimal places. (a) What proportion of fans will last at least 9000 hours? (b) What proportion of fans will last at most 7000 hours?

You drop a rubber ball off the roof of a 50 meter high building onto a paved parking lot. it bounces back up with every bounce, but not quite all the way back up to you. after the first bounce it bounces back only 80 percent of the distance it was dropped from. the pattern continues, meaning after every bounce it comes up to just 80 percent of the previous maximum height. so if before the first bounce the height is 50 meters, what height does the ball reach after the fifth bounce? round your answer to one decimal place and chose the correct response from the choices below:

Which are factor pairs of 350? choose all answers that are correct. a) 30 and 12 b) 35 and 10 c) 70 and 5 d) 2 and 125

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?