why i am still wrong

In the Northern Hemisphere, dolphins swim predominantly in a counterclockwise direction while sleeping. A group of researchers wanted to know whether the same was true for dolphins in the Southern Hemisphere (Stafne and Manger, 2004). Suppose they watched seven sleeping dolphins and recorded the percentage of time that the dolphins swam clockwise. Assume that this is a random sample and that this variable has a normal distribution in the population. The data are as follows: 79.4, 84.8, 99.6, 93.6, 89.4, 97.2, 84. Provide answers to the following to two decimal places. (a) What is the mean percentage of clockwise swimming for the dolphins observed? 89.71 (b) What is the best estimate of the standard deviation of the percentage of clockwise swimming in Southern Hemisphere dolphins? 6.90 (c) What is the 95% confidence interval for the mean percentage time swimming clockwise in Southern Hemisphere dolphins? 84.61 94.82 (d) What is the 99% confidence interval for the mean percentage time swimming clockwise in Southern Hemisphere dolphins? 83.01 96.42 (e) What is the median of the percentage of clockwise swimming for the dolphins observed? 89.4 Stafne, G. M., and P. R. Manger (2004): Predominance of clockwise swimming during rest in Southern Hemisphere dolphins. Physiology & Behavior 82, 919--926