multiple choice 6-10, thank you

Question 6 (1 point) Consider the sample 83, 74, 85, 75,88, 79, 90, 76, 77, 89,81, 72 from a normal population with population mean u and population variance 0'2. Find the 95% confidence interval for p. O a) 80.751:6.68 O b} 807513.42 O c} 80.751512 0 d) 80.751543 O e) 807513.95 \fQuestion 8 (1 point) Suppose x = 20, s=16 and n=30. What is the 90% confidence interval for u. O a) 14.20