MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER The U.S. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let x. be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 9740 observations, the sample mean interval was x, = 61.0 minutes. Let x, be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 23,585 observations, the sample mean time interval was x, = 71.8 minutes. Historical data suggest that o, = 8.49 minutes and o- = 12.48 minutes. Let #, be the population mean of x, and let u, be the population mean of x,. (a) Compute a 99% confidence interval for #, - u,. (Use 2 decimal places.) lower limit upper limit of this problem. Does the interval consist of