hello! i’ve done everything i could think of to try and answer this given question but i can’t seem to understand nor can I find solutions and videos to explain it T__T i’m preparing for college entrance tests and would love to ask for help in these particular questions:

Question 1: Mr. James, a History teacher, computed the mean grade of his 10 students in a certain class. If he would give each student a bonus of 2 points, what would happen to the mean grade of the 10 students?

Question 2: A statistics student computed the standard deviation of 25 scores and he found it to be equal to 4. If 10 were subtracted from each score, what would be the new standard deviation?

Thank you!