The Cleaning Institute conducted a survey in 2009 of 874 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 8.875 with a standard deviation of 6.617. Estimate the true mean number of times adults wash their hands per day with 95% confidence interval. We are 95% confident that the mean number of times an adult washes his or her hands is between and . (Use t=1.960 and remember to round values to 4 decimal places)