Find the mean median mode and midrange The mean phenotype

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.

Polygon abcd is a rectangle what is the area