The weight distribution of parcels sent in a certain manner is normal with mean value 12 lb and standard deviation 3.5 lb. the parcel service wishes to establish a weight value c beyond which there will be a surcharge. what value of c is such that 99% of all parcels are at least 1 lb under the surcharge weight?

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s. part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.