Can you help me step by step with the following SAS codes? I keep getting errors?

1. Use a DATA step to create a permanent working SAS data set of "birthweights" called "birthweights_2". In this DATA step, use mathematical operators (e.g., =, -, etc.) to form new variable called "birth_age" that is an estimate of the mother's age when she gave birth by subtracting the child's age (ageyr_child) from the mother's age (k9q16r).

2. Use data set "birthweights_2" formed in part 3b to test the hypothesis that the average the mother's age when she gave birth (birth_age) isdifferent than 19 years old.