The mean annual incomes of certified welders are normally distributed with the mean of $51,950 and a population standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $51,950 annually. A sample of 100 welders is taken and the mean annual income of the sample is $52,340. If the level of significance is 0.05, what conclusion should be drawn? Your answer should clearly mention the following. a) Write down the null and alternate hypothesis. b) What is the critical value and the decision rule? c) What is the test statistic? d) What is the decision and interpretation of the same?