"Time in Purgatory: Examining the Grant Lag for U.S. Patent Applications," published online by the Berkeley Electronic Press in 2003, examined grant lag (period of time between an initial patent application and its final granting, in months) for patents on record between 1976 and 1996. There were well over 1 million patents during this period, and their grant lag time had mean 28.4 months, standard deviation 19.7 months.5 Mean grant lag was found for various smaller subgroups taken from the larger population, depending on who held property rights to the patent. Tell whether each of these would have a positive or negative standardized score z:
a. Government: mean 31.1
b. Independent: mean 28.7
c. Unassigned: mean 26.4