Chemical-plant equipment costs rarely vary in proportion to size. in the simplest case, cost c varies with size 5 according to the allometric equation c= s the size exponents is typically between 0 and 1. for a wide varity of equipment types it is approximately 0.6. (a) for 0 < 81, show that cost per unit size decreases with increasing size. ("economy of scale.") (b) consider the case of a spherical storage tank. the size is commonly measured by internal volume vf. show that 8 = 2/3. on what parameters or properties would you expect quantity a to depend?