please answer a-d
A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are found to have positive BAC values. He randomly selects records from 82 such drivers in 2009 and determines the sample mean BAC to be 0.15 g/dL with a standard deviation of 0.070 g/dL. Complete parts (a) through (d) below. (a) A histogram of blood alcohol concentrations in fatal accidents shows that BACs are highly skewed right. Explain why a large sample size is needed to construct a confidence interval for the mean BAC of fatal crashes with a positive BAC. O A. Since the distribution of blood alcohol concentrations is normally distributed, the sample must be large to ensure that the sample size is greater than 5% of the population. O B. Since the distribution of blood alcohol concentrations is not normally distributed (highly skewed right), the sample must be large so that the distribution of the sample mean will be approximately normal. O C. Since the distribution of blood alcohol concentrations is not normally distributed (highly skewed right), the sample must be large to ensure that the sample size is greater than 5% of the population. O D. Since the distribution of blood alcohol concentrations is normally distributed, the sample must be large so that the distribution of the sample mean will be approximately normal. (b) Recently there were approximately 25,000 fatal crashes in which the driver had a positive BAC. Explain why this, along with the fact that the data were obtained using a simple random sample, satisfies the requirements for constructing a confidence interval. O A. The sample size is likely less than 5% of the population. O B. The sample size is likely less than 10% of the population. O C. The sample size is likely greater than 10% of the population. O D. The sample size is likely greater than 5% of the population. (c) Determine and interpret a 90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC. (Use ascending order. Round to three decimal places as needed.) O A. The lower bound is and the upper bound is . The researcher is 10% confident that the population mean BAC is in the confidence interval for drivers involved in fatal accidents who have a positive BAC value. O B. The lower bound is and the upper bound is . The researcher is 90% confident that the population mean BAC is in the confidence interval for drivers involved in fatal accidents who have a positive BAC value. O C. The lower bound is and the upper bound is . The researcher is 90% confident that the population mean BAC is not in the confidence interval for drivers involved in fatal accidents who have a positive BAC value
