Intelligent life was found in space and an anthropologist was sent to get to know these extraterrestrials. The main task of the anthropologist is to study the heights of these extraterrestrials. He found out that the aliens' lengths are normally distributed with an expected value of 234 cm and a standard deviation of 9.2 cm, if the length of the antenna on the alien's head is not taken into account. The lengths of the aliens' antennae are normally distributed with an expected value of 120 cm and a standard deviation of 20 cm. The anthropologist also noticed that the length of the alien and the length of the antenna do not depend on each other. (a) How large a proportion of aliens are less than 200 cm tall (disregarding antenna length)? (b) How many aliens have an antenna length exceeding 150 cm? (c) How many aliens have a length of more than 220 cm and an antenna length of less than 125 cm? (d) How large a proportion of aliens are 3203 55 cm tall, if the length of the antenna is taken into account