Medical Operations The director of a medical hospital feels that her surgeons perform more operations per year than the national average of 211. She selected a random sample of 15 surgeons and found that the mean number of operations they performed was 212.8. The standard deviation of the sample was 3.8. Is there enough evidence to support the director's feelings at a = 0.10? Assume that the population is approximately normally distributed. Use the critical value method and tables. compute the test- using the the z- test find the p value make a decision

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.