Question

Find the left critical value for 95% confidence interval for σ with n = 41. 26.509 24.433 55.758 59.342

Answer 1

Answer: 59.342

Step-by-step explanation:

The chi-square critical values are used to find the confidence interval for σ.

Left critical value = $\chi^2_{\alpha/2, n-1}$ [i.e. chi-square value from chi-square table corresponding to degree of freedom n-1 and significance level of $\alpha/2$]

To find : left critical value for 95% confidence interval for σ with n = 41.

Significance level : $\alpha=1-0.95=0.05$

degree of freedom = 41-1=40

Now, the  left critical value for 95% confidence interval for σ with n = 41 is the chi-square value corresponding  to degree of freedom n-1 and $\alpha/2=0.025$

=59.342  [from chi-square table ]