A health expert evaluates the sleeping patterns of adults. Each week she randomly selects 30 adults and calculates their average sleep time. Over many weeks, she finds that 5% of average sleep time is less than 6 hours and 5% of average sleep time is more than 6.4 hours. What are the mean and standard deviation (in hours) of sleep time for the population? (Round "Mean" to 1 decimal places and "standard deviation" to 3 decimal places.) Mean Standard deviation