The Cleaning Institute conducted a survey in 2009 of 841 adults asking each adult the number of times they wash their hands per day. The mean number of times those sampled washed their hands was 8.788 with a standard deviation of 5.918. Researchers would like to include a 90% confidence interval. How many degrees of freedom would be associated with the t-distribution? df = ___
With 90% confidence, we estimate the mean number of times an individual washes their hands is between __ and __(The appropriate t critical point is t = 1.647. Round the limits of your interval to 4 decimal places.)