Question

use the t distribution table to find the $t_{\alpha/2}$ value for an 80\\% confidence interval for the mean when the sample size is 14. $t_{\alpha/2}=\square$

Explanation:

Step1: Calculate degrees of freedom

Degrees of freedom $df = n - 1 = 14 - 1 = 13$

Step2: Find $\alpha$ and $\alpha/2$

Confidence level = 80%, so $\alpha = 1 - 0.80 = 0.20$, $\alpha/2 = 0.10$

Step3: Look up t-table

Find row $df=13$ and column $\alpha/2=0.10$; the value is 1.350

Answer:

1.350