Landon goes to sleep at different times and wakes up at different times. This week he kept track of his bedtime and wake up time and here is what he found. On Monday, Landon slept 8 hours, Tuesday -9 hours, Wednesday -7 hours, Thursday -6.5 hours, Friday -7.25, Saturday -8.5 hours, and Sunday -6.75 hours. What is the mean amount of hours Landon slept this week?