thanks in advance

4. Suppose a population is Normally distributed with o = 4 A random sample of 25 observations is drawn from the population and we find the sample mean of these observations is x = 12. We test the null hypothesis Ho: U = 10 and the alternative Ha: ul > 10. a. What is the value of the test statistic z? b. What is the P-value? c. Would you reject or fail to reject the null at the 5% significance level? Why? d. Would you reject or fail to reject the null at the 1% significance level