Three Years Ago,a Major Hotel Chain Purchased a Large Number

Multiple Choice

Three years ago,a major hotel chain purchased a large number of heating and air-conditioning units from three major manufacturers,A,B,and

A) Reject the null hypothesis.
B) Fail to reject the null hypothesis.
$\begin{array}{lrcrcr}\text { Brand A } & \left(R_{A}\right) & \text { Brand B } & \left(R_{B}\right) & \text { Brand C } & \left(R_{C}\right) \\\$ 80 & (2) & \$ 100 & (4) & \$ 140 & (6) \\\$ 250 & (10.5) & \$ 170 & (8) & \$ 280 & (12) \\\$ 150 & (7) & \$ 430 & (19) & \$ 100 & (4) \\\$ 70 & (1) & \$ 290 & (13) & \$ 100 & (4) \\\$ 220 & (9) & \$ 370 & (17) & \$ 340 & (15) \\\$ 300 & \underline{(14) } & \$ 420 & (18) & \$ 250 & (10.5) \\& 43.5 & \$ 350 & \underline{(16) }& &51.5\\&&&95&&\end{array}$

$$\begin{array} { l } \chi _ { .05,2 } ^ { 2 } = 5.99 \\H = \frac { 12 } { ( 19 ) ( 20 ) } \left[ \frac { ( 43.5 ) ^ { 2 } } { 6 } + \frac { ( 95 ) ^ { 2 } } { 7 } + \frac { ( 51.5 ) ^ { 2 } } { 6 } \right] - 3 ( 19 + 1 ) \\H = 4.633\end{array}$$
C) The accounting department of the hotel chain kept records on their repair and replacement costs over the last 3 years.The manager of the purchasing department randomly selected 6 brand A,7 brand B,and 6 brand C heating and air-conditioning unit records.The repair and replacement costs in dollars are summarized in the following table.At ? = .05,can we conclude that there is a significant difference in repair costs among the three brands?
$$\begin{array} { l c c } \text { Brand A } & \text { Brand B } & \text { Brand C } \\\$ 80 & \$ 100 & \$ 140 \\\$ 250 & \$ 170 & \$ 280 \\\$ 150 & \$ 430 & \$ 100 \\\$ 70 & \$ 290 & \$ 100 \\\$ 220 & \$ 370 & \$ 340 \\\$ 300 & \$ 420 & \$ 250\\&\$350\end{array}$$