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\begin{tabular}{|c|c|c|c|c|}
\hline \multirow{2}{*}{Subject} & \multicolumn{4}{|c|}{MPF (in Hz)} \\
\hline & Location 1 before & Location 1 after & Location 2 before & Location 2 after \\
\hline 1 & 6.4 & 8.0 & 6.8 & 9.4 \\
\hline 2 & 8.6 & 12.7 & 9.5 & 11.2 \\
\hline 3 & 7.4 & 8.4 & 6.6 & 10.2 \\
\hline 4 & 8.6 & 9.0 & 9.0 & 9.7 \\
\hline 5 & 9.9 & 8.4 & 9.6 & 9.2 \\
\hline 6 & 8.8 & 11.0 & 9.0 & 11.8 \\
\hline 7 & 9.1 & 14.4 & 7.8 & 9.3 \\
\hline 8 & 7.4 & 11.1 & 8.1 & 9.1 \\
\hline 9 & 6.7 & 7.3 & 7.2 & 8.0 \\
\hline 10 & 8.8 & 11.2 & 7.4 & 9.3 \\
\hline
\end{tabular}
Use a table or technology. Round your answers to two decimal places.)
(-2 6.69 ) Hz
Studdy Solution
STEP 1
1. We have paired data for each subject before and after exposure at Location 1.
2. The goal is to construct a 90% confidence interval for the mean difference in MPF at Location 1.
3. The differences are calculated as .
STEP 2
1. Calculate the differences for each subject.
2. Compute the mean and standard deviation of these differences.
3. Determine the critical value for a 90% confidence interval.
4. Calculate the confidence interval using the mean, standard deviation, and critical value.
STEP 3
Calculate the differences for each subject at Location 1:
\begin{align*}
\text{Subject 1:} & \quad 6.4 - 8.0 = -1.6 \\
\text{Subject 2:} & \quad 8.6 - 12.7 = -4.1 \\
\text{Subject 3:} & \quad 7.4 - 8.4 = -1.0 \\
\text{Subject 4:} & \quad 8.6 - 9.0 = -0.4 \\
\text{Subject 5:} & \quad 9.9 - 8.4 = 1.5 \\
\text{Subject 6:} & \quad 8.8 - 11.0 = -2.2 \\
\text{Subject 7:} & \quad 9.1 - 14.4 = -5.3 \\
\text{Subject 8:} & \quad 7.4 - 11.1 = -3.7 \\
\text{Subject 9:} & \quad 6.7 - 7.3 = -0.6 \\
\text{Subject 10:} & \quad 8.8 - 11.2 = -2.4 \\
\end{align*}
STEP 4
Compute the mean () and standard deviation () of the differences:
\begin{align*}
\bar{d} & = \frac{-1.6 - 4.1 - 1.0 - 0.4 + 1.5 - 2.2 - 5.3 - 3.7 - 0.6 - 2.4}{10} \\
& = \frac{-19.8}{10} \\
& = -1.98
\end{align*}
Calculate the standard deviation ():
STEP 5
Calculate the sum of squared differences:
Compute :
STEP 6
Determine the critical value for a 90% confidence interval with 9 degrees of freedom. Use a t-distribution table or calculator to find .
STEP 7
Calculate the confidence interval:
Substitute the values:
The 90% confidence interval for the difference in mean MPF at Location 1 is approximately:
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