3. A student wanted to know about the number of units students take during a semester. She asked 15 of her classmates in her advanced physics class. The class only has seniors who are either physics or math majors. The data is below. 15, 16, 12, 15, 17, 16, 17, 17, 18, 12, 13, 15, 16, 17, 14 a) Comment on the potential bias from her study. Is her sample representative of the population? Explain. b) Make an appropriate graph of the data and use the graph to describe the shape of the distribution.c) Find a 95% confidence interval for the number of units a college student takes. 4. Create a flow chart or diagram that show the decision process for determining which one variable test you run (Proportion Test, Z-Test, T-Test)