Chapter 9.3, Problem 11P

For Problems 7-21, please provide the following information.

(a) What is the level of significance? State the null and alternate hypotheses.

(b)Check Requirements What sampling distribution will you use? Do you think the sample size is sufficiently large? Explain. Compute the value of the sample test statistic and corresponding z value.

(c) Find the P-value of the lest statistic. Sketch the sampling distribution and show the area corresponding to the P-value.

(d) Based on your answers in parts (a) to (c). will you reject or fail to reject the null hypothesis? Are the data statistically significant at level $\alpha$?

(e)Interpret your conclusion in the context of the application.

Highway Accidents: DUI The U.S. Department of Transportation, National Highway Traffic Safety Administration, reported that $77\%$ of all fatally injured automobile drivers were intoxicated. A random sample of 27 records of automobile driver fatalities in Kit Carson County, Colorado, showed that15 involved an intoxicated driver. Do these data indicate that the population proportion of driver fatalities related to alcohol is less than $77\%$ in Kit Carson County? Use $\alpha =0.01$.