Hi, Someone can help me with this questions. Thanks

I need to asnwer this cuestion with R Studio

A group of 400 employees is randomly selected at a large company. They are asked if they spend greater than 4 hours a day looking at a computer screen. 313 responded yes.

a). Find a 95% confidence interval for the population proportion of employees that spend greater than 4 hours a day looking at a computer screen.

b). Assume that the sample proportion stays the same but the number of employees selected is increased to 1400. Find an 85% confidence interval for the population proportion of employees that spend greater than 4 hours a day looking at a computer screen.

c. Is the confidence interval in part b wider or more narrow than the interval in part a? Explain the result in relation to the sample size and level of confidence.

2) Write a function that takes as input the sample proportion, the margin of error, and the confidence level and outputs the required sample size. Using your function, answer the following question: It is believed that 20% of adults over the age of 50 never graduated from high school. We wish to see if this percentage is the same among the 25 to 30 age group. How many of this younger age group must be surveyed in order to estimate the proportion of non-graduates to within 5% with 95% confidence?