A researcher measured the weight of 36 koalas. The sample had a mean of 2.4kg and a sample standard deviation of 0.5 kg. Which formula should they use to determine the 99% confidence interval for the mean. We want to use t-tables only. A 99% CL of the mean = 2.4 + (2.58)(0.5) B 99% CL of the mean = 2.4 + (2.72)(0.5) 99% CL of the mean = 2.4 + (2.72)(0.25) D 99% CL of the mean = 2.4 + (2.58)(0.08) E 99% CL of the mean = 2.4 + (2.72)(0.08)