please answer the question below

In the figure a nonconducting spherical she" of inner radius a = 2.23 cm and outer radius b = 2.43 cm has {within its thickness) a positive volume charge density p = A/r, where A is a constant and r is the distance fram the center of the shell. In addition, a small ball of charge q = 45.0 fC is located at that center. What value should A have if the e'ectric field in the shen (a s b) is to be uniform? Number Units