Two hundred fish caught in Cayuga Lake had a mean length of 14.3 inches. The population standard deviation is 2.6 inches. (Give your answer correct to two decimal places.) Solution (a) Given a=0.1, Z(0.05)=1.645 (from standard normal table) Lower limit = xbar-Z*s/vn = 14.3 -1.645*2.6/sqrt(200) =13.99757 Upper limit = xbar+Z*s/vn = 14.3 +1.645*2.6/sqrt(200) =14.60243 (b) Given a=0.02, Z(0.01) =2.33 Lower limit = xbar-Z*s/vn = 14.3 -2.33*2.6/sqrt(200) = 13.87163 Upper limit = xbar+Z*s/vn = 14.3 +2.33*2.6/sqrt(200) =14.72837.