1. Blood pressure is described by two numbers: systolic pressure and diastolic pressure (measured in mm of Hg). A study showed systolic pressure to be normally distributed with a mean of 125 and a standard deviation of 15, and the diastolic pressure to be normally distributed with a mean of 84 and a standard deviation of 9. Two study participants are randomly selected and their blood pressures are measured. The first participant had a systolic reading of 100 mm of Hg, while the second had a diastolic reading of 75 mm of Hg. Which participant had a lower reading with regard to the study population?
8. The annual number of earthquakes, the world over, is a random variable having approximately a normal distribution with m=20.8(mutte symbol). What is the standard deviation of this distribution if the probability is 0.40 that there will be less than 15 earthquakes?