= 68 EBM = zα/2 ⋅ = 3; σ The confidence level is 90% (CL=0.90) ; zα/2 = z.05 = 1.645 SOLUTION A If we the sample size to 100, we the error increase decrease n bound. =1.645⋅ When = 100: EBM = = 0.4935 zα/2 n ⋅ SOLUTION B If we the sample size to 25, we the error decrease increase n bound. = When = 25: EBM = = 1.645⋅ 0.987 n zα/2 ⋅ Summary: Effect of Changing the Sample Size
= 68 EBM = zα/2 ⋅ σ = 3; The confidence level is 90% (CL=0.90) ; zα/2 = z.05 = 1.645 SOLUTION A If we increase the sample size n to 100, we decrease the error bound. When n = 100: EBM = zα/2 ⋅ =1.645⋅ = 0.4935 SOLUTION B If we decrease the sample size n to 25, we increase the error bound. When n = 25: EBM = zα/2 ⋅ = 1.645⋅ = 0.987 Summary: Effect of Changing the Sample Size
ch8_confidenceintervalsdknown.docx