A sample of size 18 has been collected from a normal population with variance 3, and is saved in the variable with name 'data' in R. Below are some R output of the sample. > median (data) [1] 26 > mean (data) [1] 25.94444 > var (data) [1] 18.52614 > sd (data) [1] 4. 304201 Find the 80% confident interval for the unknown population mean. [25.4219 , 26.4670] [24.893 , 26.9957] [24.6744,27.2145] Non of them [25.1443 , 26.7446] [25.5362 , 26.3527]