Hi 95% confident ⇒ z = 1.96 (See below) σ = 3000, ME = 1000 How large of a sample size is required? ME large ⇒ expect small sample size0r n = n = = 34.5744 0r sample Size = 35 (always round Up) = CI z = value 90% z =1.645 92% z = 1.751 95% z = 1.96 Invnorm(.975) 2-sided (.95 + .05/2 = .975 ) 98% z = 2.326 99% z = 2.576 Wish You the Best in your Studies.