2. A health researcher measured the weight of 162 12-month old girls in a low-income community. The study yielded the mean of 8.77 kg and the standard deviation of 0.98 kg. (2a) Use the theory of simple random sampling to estimate the 95% confidence interval of the expected mean weight of 1 year old girls in this community. Justify all steps both algebraically and graphically. (10 points for the algebra and 5 points for the graph) (2b) According to WHO (World Health Organization), the mean weight of 12 month old girls is about 8.91kg. Does this study suggest that this community's girls are underweight? Set up hypotheses. (5 points) Ho : Ha : (2c) Test your hypotheses with the significance level of a = 0.05. Justify all steps both algebraically and graphically. (10 points for the algebra and 5 points for the graph)