thank you for your help!

Let X be a random variable representing the dividend yield of Australian bank stocks. We may assume that X has a normal distribution with standard deviation o = 2.8%. Now, suppose we wish to test the null hypothesis that / =6.4% against the alternative that # > 6.4% using a level of significance of a =.05. To do so, a random sample of 16 Australian bank stocks is observed and has a sample mean of I = 8.91%.What is the value of the test statistic? -0.224 - 3.586 3.586 0.896