Suppose that insurance companies did a survey. They randomly surveyed 450 drivers and found that 300 claimed they always buckle up. We are interested in the population proportion of drivers who claim they always buckle up. NOTE: If you are using a Student's t-distribution, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) Correct! We use the standard normal distribution to create confidence intervals about the population proportion. Part (d) Construct a 95% confidence interval for the population proportion who claim they always buckle up. (1) State the confidence interval. (Round your answers to four decimal places.) (1) Sketch the graph. = O C.L. = O O O P' (iii) Calculate the error bound. (Round your answer to four decimal places.) Part (e) If this survey were done by telephone, list three difficulties the companies might have in obtaining random results.