Question 1158983
Sample size n=15
mean is sum/15=3.787
variance is sd^2 =0.9426
sd=0.9709
median is  the 8th (middle) of ordered data from smallest to largest.  Order the data and the 8th one will be 3.4

You must order the data from small to large or vice versa for the median. It is the middle point or the average of two middle points if there are an even number of items. The median of 5 ordered is 3, 2 on either side and one unique middle.  The median of 8 is half way between the 4th nd the 5th, since there is no unique middle.