Select all the assumptions and conditions that are required

Select all the assumptions and conditions that are required to carry out a paired t-test on two groups of data collected from a single random sample:

	the data values between the groups are paired
	the differences between the paired population data are independent
	the groups of data are normally distributed
	the population standard deviation of the differences between the paired data values is known
	the differences between the paired population data are normally distributed
	the groups of data are independent

Data values between the groups are paired

groups of data are independent

the groups of data are normally distributed