Solve these 1 through 4 questions please

3. To test the null hypothesis that the population mean is # = #o with a single sample of size n, we require (say) that n > 30. Our test statistic TS is I - Ho where I is the sample mean and s is the sample standard deviation. The degrees of freedom is dof = n - 1. (b) For a left-tailed test, we may compute -ta = InvT(a, dof) and check that the test-statistic falls in the tail. Or we may instead compute P = tcdf (|TS| , co, dof), then check that P 99 ? ii. Explain what we would conclude if we rejected the null hypothesis with a left-tailed test. iii. Can we reject the null hypothesis at level of significance o = 0.05, using a left-tailed test? iv. Can we reject the null hypothesis at level of significance a = 0.01, using a left-tailed test