Which of the following formulae is used in the computation of the confidence interval for the mean?
A) $\sqrt { \frac { ( X - M ) ^ { 2 } } { N } }$
B) $\frac { X - M } { \sigma }$
C) $M \pm \frac { \left( t _ { .05 } \right) ( S ) } { \sqrt { N } }$
D) $\frac { \sum ( X - M ) ^ { 2 } } { N }$

Question

Quizplus · Accepted Answer

The correct formula for computing the confidence interval for the mean is $M \pm \frac { \left( t _ { .05 } \right) ( S ) } { \sqrt { N } }$, where $M$ is the sample mean, $t_{.05}$ is the t-score corresponding to the desired confidence level (e.g., 95%), $S$ is the sample standard deviation, and $N$ is the sample size. This formula is used when the population standard deviation is unknown and the sample size is relatively small.

Which of the Following Formulae Is Used in the Computation (X−M)2N\sqrt { \frac { ( X - M ) ^ { 2 } } { N } }N(X−M)2​​

Which of the Following Formulae Is Used in the Computation $\sqrt { \frac { ( X - M ) ^ { 2 } } { N } }$