Question

determine the critical value for a left tailed test of a population mean at the α = 0.001 level of significance based on a sample size of n = 10. round to three decimal places
oa. 3.733
ob. 3.686
oc. - 2.002
od. - 3.733

Explanation:

Step1: Determine the degrees of freedom

The degrees of freedom \(df=n - 1\). Given \(n = 10\), so \(df=10 - 1=9\).

Step2: Locate the critical value in the t - distribution table

For a left - tailed test with \(\alpha = 0.001\) and \(df = 9\), we look up the value in the t - distribution table. The critical value for a left - tailed test is negative. In the t - distribution table, for \(df=9\) and one - tailed \(\alpha = 0.001\), the value is \(t=-3.733\).

Answer:

D. - 3.733