Sungho YoonPublic health 391BNov. 20 2015Assignment 5Hypothetical scenario: The average total cholesterol for adult Americans over the age of 30 is 200 mg/dL. Researchers took a random sample of 45 adults in central Massachusetts. Some of the participants were advised by their doctor to exercise to lower their cholesterol and some were not. The 45 participants were followed for 8 weeksand their cholesterol levels were recorded again. Exercise 1: We would like to know whether the average total cholesterol in our sample at baseline is different from the average total cholesterol of the typical American adult. 1 . What is the point estimate? (1 point) - 211.982 . What are your null and alternative hypotheses? (2 points) - H(0) The average total cholesterol sample = the average total cholesterol for typical American adults 200mg/dl - H(a) The average total cholesterol sample does not equal the average total cholesterol for typical American adults 200mg/dl3 . What assumptions must be met in order to calculate a one sample test statistic? Do you think the assumptions are satisfied? State the ones you think have not been satisfied, if any, and indicate why. (3 points) - Random sample: satisfied, explicitly stated- n >= 30: satisfied, 42 participants- not extremely skewed: normally distributed as see in histogram- My assumption is that it is independent, normal distribution and there is no outliers4 . Regardless of your answer to Question 3, calculate a one-sample test statistic and report the p-value for your specific alternative hypothesis (i.e. one-sided or two-sided). (2points) - T = 1.7848, df = 41- The p-value is 0.0817- The alternative hypothesis: true mean is not equal to 200- 95 percent confidence interval 198.4248 225.52765 . 5. Based on your answer to Question 4, do you have sufficient evidence to reject the null hypothesis? (1 point) - Based on my answer to question 4, I do not have sufficient evidence to reject the null hypothesis. 6 . Was this change statistically significant? Explain using the p-value for a two-sided hypothesis only. (1 point) - Not statistically significant since p value for a two-sided hypothesis is not < 0.05Exercise 2: We would like to determine whether average cholesterol levels are lower for individuals that were told to exercise compared to those that were not, after 8 weeks. 1 . What are the null and alternate hypotheses? (2 points)- Difference in mean cholesterol between treatment and control is <0 - H(o) - No difference between cholesterol after exercise and cholesterol control = 0- H(a) - No difference between cholesterol after exercise and cholesterol control < 02 . What assumptions must be met in order to calculate a two sample test statistic? (3 points) - Since this is data on individuals we believe each observation is independent.- Sufficient size sample- Approximately normal- Unbiased point estimate3 . Conduct an appropriate two-sample test and report the p-value for your specific alternative hypothesis. (3 points)p-value = 0.3794. Indicate whether the cholesterol levels are statistically different between the two groups using a one sided p-value. Explain your result (in 1-2 sentences) to a person who does not know statistics. (2 points)- It is unable to reject null hypothesis because my p-value is greater than