Avariable of two populations has a mean of 30.7 and a standard deviation of 32.1 for one of the population and it mean if 30.7 and it’s dinner deviation of 26.6 for the other population for independent samples of size 6211 and 4581 respectively find the mean and standard deviation of x1 minus x2

Jack has a rectangular piece of land, the area of which is represented by a1 = 9.5l. his brother has a different rectangular piece of land, the area of which is represented by a2 = l(14 − l). let a represent the area in square meters and l represent the length in meters of the pieces of land. the two equations plotted on a graph meet at a point as shown in the image