A Researcher Is Estimating the Average Difference Between Two Population

Multiple Choice

A researcher is estimating the average difference between two population means based on matched-pairs samples.She gathers data on each pair in the study resulting in: $$\begin{array} { | r | r | r | } \hline \text { Pair } & \text { Group 1 } & \text { Group } 2 \\\hline 1 & 10 & 12 \\\hline 2 & 8 & 9 \\\hline 3 & 11 & 11 \\\hline 4 & 8 & 10 \\\hline 5 & 9 & 12 \\\hline\end{array}$$ Assume that the data are normally distributed in the population.To obtain a 95% confidence interval, the table t value would be _______.

A) 2.132
B) 1.86
C) 2.306
D) 2.976
E) 2.776