please help im stuck!!!

(3 points) A random sample of 110 observations produced a mean of E = 30.5 from a population with a normal distribution and a standard deviation 6 = 3.84. (For each of the following, rounded to 2 decimals) (a) Find a 99% confidence interval for y S l4 S (b) Find a 90% confidence interval for y S I4 S (c) Find a 95 % confidence interval for p S I4 s (3 points) A random sample of n measurements was selected from a population with standard deviation 0' = 14 and unknown mean u. Calculate a 95 % confidence interval for [4 for each of the following situations: (rounded to 2 decimals) (a)n = 40, 3-6 = 104.2 5 [4 S (b) n = 65, Tc = 104.2 5 5 (c)n = 80, 3c = 104.2 S # S (d) In general, we can say that for the same confidence level. increasing the sample size the margin of error (width) of the confidence interval. (Enter: "DECREASES", "DOES NOT CHANGEII or \"INCREASES", without the quotes.)