Help!!!Most points and brainlest to best answered
1.a company that has 360 employees was interested in determining the average salary of its employees, to figure this out the company divided the employees in to four groups;managers,drivers,office staff, and production staff,and then randomly selected employees from each group.What type of sampling method did they use?
a.stratified random sampling
b.systematic sampling
c. cluster sampling
d. simple random sampling
