8. Concussion in the National Football League (NFL) remains an important issue. Obser vations from two consecutive 6-year periods (1996-2001 and 2002-2007) were compared to determine changes in the circumstances associated with the injury. observed expected 1996-2001 2002-2007 total 1996-2001 2012-2 007 tackling 251 197 tackling 228.2 tackled 225 200 tackled 216.5 blocking 128 119 blocking 125.8 blocked 104 147 blocked 127.9 other 79 45 other total total (a) Fill in all of the row and column totals in the "observed" table above. (b) Give a suitable hypothesis to address the question addressed above. (c) Fill in the missing values in the "expected" table. (d) Explain how you would compute the y' test statistic. (e) The value of the test statistic is 16.6068. What do you conclude about concus- sions!"