Example A certain type of magnetic disk must function in an environment where it is
exposed to corrosive gases. It is known that 10% of all such disks have
lifetimes less than or equal to 100 hours, 50% have lifetimes greater than 100
hours but less than or equal to 500 hours and 40% have lifetimes greater than
500 hours. Let Z represent the number of hours in the lifetimes of a randomly
chosen disk
a) Find P(Z<=500)

Ms. b is a 40-year-old woman who is the ceo of a struggling company. lately she has been experiencing headaches that are so severe that she gets dizzy and nauseated, and she is unable to carry out her usual daily routines. she reports that they usually begin as a throbbing pain in the left temple and then seem to spread throughout her head. a diagnosis of migraine headache is made after several tests. based on the patient history and signs and symptoms, discuss this type of headache and its physiological causes. discuss the available treatments to prevent and/or relieve the patient’s migraine.