Question

Using a graphing calculator find the value of tα/2 for a 95% confidence interval when the sample size is 24.

Answer 1

We will, first of all, calculate the alpha level

$\alpha=1-confidence\text{ interval}$

The given confidence interval is

$=95\text{ \%=0.95}$

Therefore, the alpha level will be

$\begin{gathered} \alpha=1-0.95 \\ \alpha=0.05 \end{gathered}$

for,

$\begin{gathered} \frac{\alpha}{2,} \\ we\text{ will have} \\ \frac{\alpha}{2}=\frac{0.05}{2}=0.025 \end{gathered}$

The degree of freedom is

$\begin{gathered} df=n-2 \\ \text{where n=sample size}=24 \\ df=24-2 \\ df=22 \end{gathered}$

Using a graphing calculator,

$t_{\frac{\alpha}{2}}=2.073873$

Hence ,

T(ALPHA/2) VALUE= 2.073873