ge activities CHALLENGE ACTIVITY 6.2.1: Confidence intervals for population means. 402312.2337620.qx3zqy7 V Jump to level 1 1 The additional growth of plants in one week are recorded for 11 plants with a 2 sample standard deviation of 2 inches and sample mean of 10 inches. t* at the 0.05 significance level = Ex: 1.234 Margin of error = Ex: 1.234 Confidence interval = [ Ex: 12.345 Ex: 12.345 [smaller value, larger value]