A sample of 18 observations taken from a normally distributed population produced the following data: 28.5 27.4 25.4 25.2 31.4 23.4 26.4 24.2 28.5 37.2 23.9 28.5 27.5 25.2 27.1 25.1 22.4 22.7 Round your answers to three decimal places. b. Make a 99% confidence interval for μ. ( Enter your answer; confidence interval, lower bound ,Enter your answer; confidence interval, upper bound  ) c. What is the margin of error of estimate for μ in part b? E= Enter your answer; margin of error

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.