The principal randomly selected six students to take an aptitude test.Their scores were: $$\begin{array} { l l l l l l }
71.6 & 81.0 & 88.9 & 80.4 & 78.1 & 72.0
\end{array}$$ Determine a 90% confidence interval for the mean score for all students.
A)(73.26, 84.07)
B)(84.07, 73.26)
C)(83.97, 83.97)
D)(73.36, 83.97)

Question

The principal randomly selected six students to take an aptitude test.Their scores were: $$\begin{array} { l l l l l l } 
71.6 & 81.0 & 88.9 & 80.4 & 78.1 & 72.0
\end{array}$$ Determine a 90% confidence interval for the mean score for all students.
A)(73.26, 84.07)
B)(84.07, 73.26)
C)(83.97, 83.97)
D)(73.36, 83.97)

Quizplus · Accepted Answer

The sample mean and standard deviation are calculated, and using the t-distribution for a small sample size, the 90% confidence interval is computed as (73.36, 83.97).

The Principal Randomly Selected Six Students to Take an Aptitude 71.681.088.980.478.172.0\begin{array} { l l l l l l } 71.6 & 81.0 & 88.9 & 80.4 & 78.1 & 72.0\end{array}71.6​81.0​88.9​80.4​78.1​72.0​

The Principal Randomly Selected Six Students to Take an Aptitude $\begin{array} { l l l l l l } 71.6 & 81.0 & 88.9 & 80.4 & 78.1 & 72.0\end{array}$