118 Suppose that the insurance companies did conduct a survey They randomly surveyed 400 drivers and found that 320 claimed they always buckle up We are interested in the population proportion of drivers who claim they always buckle up a i x ii n iii p b Define the random variables X and P in words c Which distribution should you use for this problem Explain your choice d Construct a 95 percent confidence interval for the population proportion who claim they always buckle up i State the confidence interval ii Sketch the graph iii Calculate the error bound e If this survey were done by telephone list three difficulties the companies might have in obtaining dem rosults