Open Excel File, "Question 2"

Emergency Room Wait Times are a huge concern for residents of Central City, so you decide to look into this and see how bad the problem is. You obtain a sample of patient ER wait times and the times (in hours) of each was recorded. Use a normal probability plot to assess whether the sample data could have come from a population that is normally distributed.

a) Construct a normality plot for this data. (Submit graph only)

To construct a normality plot:

1. Arrange your x-values in ascending order.

2. Calculate fi = (i-0.375)/(n+0.25), where i is the position of the data value in the. ordered list and n is the number of observations.

3. Find the z-score for each fi 4. Plot your x-values on the horizontal axis and the corresponding z-score.

b) Determine the correlation coefficient between your x-values and your z-scores.

c) Using the correlation coefficient of the normal probability plot, is it reasonable to conclude that the population is normally distributed? This is true if the coefficient of correlation is greater than the critical value for the sample size. (See File "Critical Values").

d) What does this tell you about the ER wait times in Central City?

Excel File, "Question 2"