Five independent samples, each of size n are to be drawn from a normal distribution where sigma is known

A variable is an object that you are trying to measure. It has two types; independent and dependent variable. An independent variable is a variable that is not affected b other variables. A dependent variable on the other hand is a variable that depends on the other variables. Suppose you want to know the quality of sleep of the students in their academic performance. The quality of sleep is the independent variable and the academic performance is the dependent variable.