Are Repair Times for Brand a Systematically Higher Than the Repair

Essay

Are repair times for brand A systematically higher than the repair times for brand B? Test at a = .05.
B.H₀: D_A and D_B are identical,H_A: D_A is shifted to the right of D_B
$$\begin{array} { r l l l l l l l l l } \text { Brand A } & 160 & 159 & 171 & 155 & 136 & 128 & 173 & 143 & \\\mathrm {~T} _ { \mathrm { A } } = & ( 13.5 ) & + ( 12 ) & + ( 15 ) & + ( 11 ) & + ( 8 ) & + ( 4 ) & + ( 16 ) & + ( 10 ) & = 89.5 \\\text { Brand B } & 125 & 160 & 140 & 131 & 119 & 123 & 135 & 134 & \\\mathrm {~T} _ { \mathrm { B } } = & ( 3 ) & + ( 13.5 ) & + ( 9 ) & + ( 5 ) & + ( 1 ) & + ( 2 ) & + ( 7 ) & + ( 6 ) & = 46.5\end{array}$$ T = 89.5
From table A15 for n₁ = 8,and n₂ = 8,T_U = 84
Since 89.5 > 84,we reject H₀ and conclude that the repair times for brand A is higher than the repair times for brand