p-hat...is this right?

Suppose that the true proportion of drivers who never wear a seat belt is 23% In a random sample of n = 200 drivers, 50 individuals say they never wear a seat belt when driving.

1. (1 pts)
Give a numerical value for p-hat.
Response: .23

2. (1 pts)
Calculate the standard deviation for the sampling distribution of p-hat. Give answer to 4 decimals.
Response: .0298

3. (1 pts)
In a different survey of 400 people, 100 people say they never wear a seat belt. Calculate p-hat.
Response: .23

4. (1 pts)
For the survey of 400 people, calculate the standard deviation for p-hat. Give answer to 4 decimals.
Response: .0210

Show your work and explain your reasoning and one might be able to help you - unless that would constitute taking your exam for you.