In a study of reaction times, the time to respond to a visual stimulus (x) and the time to respond to an auditory stimulus (y) were recorded for each of 8 subjects. Times were measured in thousandths of A second. The results are presented in the following table.

$\begin{array} { c c }
\hline \text { Visual } & \text { Auditory } \
\hline 185 & 244 \
204 & 244 \
242 & 247 \
209 & 245 \
191 & 243 \
250 & 249 \
155 & 237 \
188 & 245 \
\hline
\end{array}$

Compute a point estimate for the mean auditory response time for subjects with a visual response time of .
A) 249.98
B) 247.11
C) 244.25
D) 244.24

Question

In a study of reaction times, the time to respond to a visual stimulus (x) and the time to respond to an auditory stimulus (y) were recorded for each of 8 subjects. Times were measured in thousandths of A second. The results are presented in the following table.

$\begin{array} { c c } 
\hline \text { Visual } & \text { Auditory } \
\hline 185 & 244 \
204 & 244 \
242 & 247 \
209 & 245 \
191 & 243 \
250 & 249 \
155 & 237 \
188 & 245 \
\hline
\end{array}$

Compute a point estimate for the mean auditory response time for subjects with a visual response time of .
A) 249.98
B) 247.11
C) 244.25
D) 244.24

Quizplus · Accepted Answer

To estimate the mean auditory response time for subjects with a visual response time of x, we need to first identify the observations in the sample that correspond to a visual response time of x. Then we can calculate the sample mean of the corresponding auditory response times.

Looking at the table, we do not see any specific value of x given to us. So, we can choose any value for x to compute the estimate. Let's choose x = 200.

Visual Response Time = 200

$\begin{array} { c c } 
\hline \text { Visual } & \text { Auditory } \
\hline 204 & 244 \
191 & 243 \
188 & 245 \
\hline
\end{array}$

The corresponding auditory response times are 244, 243 and 245. The sample mean of these values is (244+243+245)/3 = 244. Therefore, a point estimate for the mean auditory response time for subjects with a visual response time of 200 is 244.

However, we need to choose from the given options. As we can see that option B, 247.11, is the closest to our calculated estimate of 244. Hence, B is the correct answer.

In a Study of Reaction Times, the Time to Respond