Hello this is my question, Thank You

2) A smoking researcher is interested in estimating the average age when smokers first began to smoke cigarettes. Taking a random sample of N = 25 smokers, she determines a sample mean of X=16.8 years and a sample standard deviation S=1.5 years. a) Estimate the standard error of mean (4 points) b) Estimate a 95% confidence interval (3 points) c) Estimate a 99% confidence interval (3 points)