Answer the questions...no need detail explanation

Question 1

For a given confidence level and sample size, which of the following is true in the interval estimation of the population mean when o is known? A. If the sample standard deviation is smaller, the interval is wider. B. If the population standard deviation is greater, the interval is narrower. C. If the population standard deviation is smaller, the interval is wider. D. If the population standard deviation is greater, the interval is wider.We draw a random sample of size 26 from the normal population with variance 2.3. If the sample mean is 12.8, what is a 99% confidence interval for the population mean? A. [12. 0338, 13.5662) B. /11. 6381, 13.9619) C. [12. 1082, 13.4918) D. [11.7508, 13.8492)