Yes I need help with x question and please check if my other answers are correct

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

Deepak plotted these points on the number line. point a: –0.3 point b: – 3 4 point c: – 11 4 point d: –0.7 which point did he plot incorrectly?

The students in a class were asked how many siblings they have. the data obtained is represented in the dot plot. the number of students who have no siblings is . the number of students who have three or more siblings is .