Listed below are speeds (mi/h) measured from traffic on a busy highway. This simple random sample was obtained at 3:30 P.M. on a weekday. Use the sample data to construct a 95% confidence interval estimate of the population standard deviation.
62 64 64 55 64 54 59 58 59 60 69
The confidence interval estimate is ___ mi/h < sigma < ____ mi/h. (Round to one decimal place as needed.)
