Recently, twenty-five economics conferences were announced. Three conferences last one day. Ten last two days. Ten last three days. Two lasted four days. Let X = length (in days) of an economics conference. (Round to two decimal places, where required)

1. The median value of X is , the first quartile value is , and the third quartile value is .
2. The 85th percentile value of X is and the 15th percentile value of X is
3. The sample mean is and standard deviation of days of the conferences is .