Calculate the Population Standard Deviation. 1  Calculate the mean or average of each data set. 2  Add up all the numbers in a data set and divide by the total number of pieces of data. 3  For example, if you have found numbers in a data set, divide the sum by 4.4  This is the mean of the data set.alculate the Population Standard Deviation. 1  Calculate the mean or average of each data set. 2  Add up all the numbers in a data set and divide by the total number of pieces of data. 3  For example, if you have found numbers in a data set, divide the sum by 4.
It takes about three days to four days for your milk to come in, if youâre a first-time mum. If you've had a baby before, it can happen earlier than this. Your breasts will start to feel full a couple of days after giving birth, which is a sign that your milk is coming in.
answers from Los Angeles on. It takes a whole lot longer than 2-4 hours for milk to spoil. Milk is good out at room temperature for up to 7 or 8 hours-it just isn't cold-and we've gotten used to milk being ice cold.nswers from Los Angeles on. It takes a whole lot longer than 2-4 hours for milk to spoil. Milk is good out at room temperature for up to 7 or 8 hours-it just isn't cold-and we've gotten used to milk being ice cold.