Hey I'm having a hard time with this question, thanks for helping

There is nothing missing actually, that why i needed help. Thanks

Suppose you flip a coin three times. For every head, you receive two points, and for every tail, you lose one point.

a) Develop the sampling distribution for the mean number of points you receive from flipping a coin three times. (Use a table)

b) What is the standard error for the sampling distribution?

c) What is the probability that the mean number of points you receive on three flips is less than 1.1?