5. The heights of a certain population of corn plants follow a normal distribution with mean 145 cm and standard deviation 22 cm. Find (a) The proportion of corn plants with a height more than 160 cm lb) The height that is the 70* percentile (c) The height of a certain corn plant given that only 1096 of corn plants exceed it in height (d) The symmetric interval such that 6096 of the heights falls within the interval