Find the range, variance, and standard deviation for each of the two samples, then compare the two sets of results.
-When investigating times required for drive-through service, the following results (in seconds)were obtained. $$\begin{array} { l | l | l | l | l | l | l | l | l }
\text { Restaurant A } & 120 & 123 & 153 & 128 & 124 & 118 & 154 & 110 \
\hline \text { Restaurant B } & 115 & 126 & 147 & 156 & 118 & 110 & 145 & 137
\end{array}$$
A)Restaurant A: 44; 285.64; 16.15
B)Restaurant A: 46; 260.79; 16.15 Restaurant B: 46; 260.79; 16.90 Restaurant B: 44; 285.64; 16.90
C)Restaurant A: 44; 260.79; 16.15
D)Restaurant A: 46; 260.79; 16.90 Restaurant B: 46; 285.64; 16.90 Restaurant B: 44; 285.64; 16.15

Question

Find the range, variance, and standard deviation for each of the two samples, then compare the two sets of results.
-When investigating times required for drive-through service, the following results (in seconds)were obtained. $$\begin{array} { l | l | l | l | l | l | l | l | l } 
\text { Restaurant A } & 120 & 123 & 153 & 128 & 124 & 118 & 154 & 110 \
\hline \text { Restaurant B } & 115 & 126 & 147 & 156 & 118 & 110 & 145 & 137
\end{array}$$
A)Restaurant A: 44; 285.64; 16.15
B)Restaurant A: 46; 260.79; 16.15 Restaurant B: 46; 260.79; 16.90 Restaurant B: 44; 285.64; 16.90
C)Restaurant A: 44; 260.79; 16.15
D)Restaurant A: 46; 260.79; 16.90 Restaurant B: 46; 285.64; 16.90 Restaurant B: 44; 285.64; 16.15

Quizplus · Accepted Answer

For Restaurant A, the range is the difference between the maximum and minimum values, which is 154 - 110 = 44. The variance and standard deviation require calculation. The mean of Restaurant A's times is (120 + 123 + 153 + 128 + 124 + 118 + 154 + 110) / 8 = 1030 / 8 = 128.75. The variance is the average of the squared differences from the Mean: $\frac{(120-128.75)^2 + (123-128.75)^2 + ... + (110-128.75)^2}{8} = 260.79$. The standard deviation is the square root of the variance, which is approximately 16.15. The choices do not provide the calculations for Restaurant B, but the correct values for Restaurant A match choice C.

Find the Range, Variance, and Standard Deviation for Each of the Two