A physical therapist wants to know if football players recover full strength following injuries due to a rehabilitation program, or if their strength is less than that of never-injured guards. A group of seven never-injured guards was given a strength test as well as a separate group of six injured guards who had finished a rehabilitation program. The following strength ratings were recorded. What is the directional null hypothesis in terms of the variables in the study?

Never-injured (X1) ( X 1) 2 Injured (X2) ( X 2 ) 2 302 91204 297 88209 306 93636 300 90000 258 66564 250 62500 239 57121 245 60025 280 78400 270 72900 265 70225 262 68644 274 75076 Sum 1924 632226 1624 442278 Average 274.8571 76032.2857 270.6667 73713