Question

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 31 records of automobile driver fatalities in Kit Carson County, Colorado, showed that 18 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 α = 0.01. Solve the problem using both the traditional method and the P-value method. Since the sampling distribution of p̂ is the normal distribution, you can use critical values from the standard normal distribution as shown in the table of critical values of the z distribution. (Round the test statistic and the critical value to two decimal places. Round the P-value to four decimal places.)

test statistic	=
critical value	=
P-value	=

Answer 1

Date Solucetion payer & given that: _ 12311x318 y de Diol 2058 p=n in The Null and alternative hypothesis- Ho! Pa 0.77 VS Hi. P20 77. l-p=0.23 21 The test statistic - ²-P - 0.58 -0.77 0.77 0.23 31 v Añ -0.19 0.076 Z: -2.505 Critical values. de viol it is one tajned, Zools the -o o z .83 2-2.505 P-value: - we it is know left that tailed P-value: PLZ using A Normal -2.585) table - Decision! based on Critical value: - zy zo if Reject Ho ie - za-z if reject Ho -2.505< -2.33

page-1 we Reject voor based on p-value: p-value ca il - 0.0061 Tool Reject to 1 iwe Reject Ho 1 Conclusion e there is sufficient evidence to conclude that the population peopoetics of drivee Fatalities related 40 celohol is less- than 77 7. in kit Caeson County