In an examination given to students at a large number of different schools, the mean grade was 70.55 and the standard deviation was 5. At one particular school where167 students took the examination, the mean grade was 74.0775. Test the hypothesis that the mean grade of the students has changed, using the significance level 0.05. 

1. Choose the null hypothesis and alternative hypothesis. 

2. Choose the type of test (one sided or two sided) and statistical method. 

3. Choose the test statistics value and table value. 

4. Choose the conclusion of the test. For any wrong selection 5% mark will be reduced from the total.