need a little help

A sample mean, sample size, population standard deviation, and confidence level are provided. Use this information to complete parts (a) through (c) below. x = 30. n =25. o =3. confidence level = 90% a. Use the one-mean z-interval procedure to find a confidence interval for the mean of the population from which the sample was drawn. The confidence interval is from to (Type integers or decimals rounded to one decimal place as needed.) b. Obtain the margin of error by taking half the length of the confidence interval. What is the length of the confidence interval? (Type an integer or decimal rounded to one decimal place as needed.)