6. Ken has set a daily jogging goal for himself of 3 miles. For four days of the week he has not met his daily goal. These are the percentages of his daily goal that he did achieve: day 1: 85%, day 2: 80%, day 3: 90%, day 4: 90%. How many miles must her run on the fifth day so that he can have achieved his goal over a 5-day period?