2. A study compared oral diversity between croplands and wetlands. Independent random samples of 126 cropland regions and 98 wetland regions were obtained in the Southern Great Plains. The cropland regions contained an average of 14.06 native oral species, with a standard deviation of 4.83; the wetland regions had an average of 15.36 and a standard deviation of 4.95. [a] Test if the mean number of native oral species is lower in cropland regions. Use the 1% significance level. [8 marks) Obtain a two-sided 99% confidence interval for the difference in mean number of oral species between cropland and wetland regions. (4 marks)