o,and o,Known Population means, Assumptions: independent samples Samples are randomly and independently drawn o and 02 known population distributions are normal or both sample sizes o1 and o2 unknown are≥30 Population standard deviations are known Statistics for Managers Using Microsoft Excel Chap9-9Statistics for Managers Using Microsoft Excel Chap 9-9 Population means, independent samples σ1 and σ2 known σ1 and σ2 Known Assumptions:  Samples are randomly and independently drawn  population distributions are normal or both sample sizes are  30  Population standard deviations are known σ1 and σ2 unknown