Question

The National Highway Traffic Safety Administration reported the percentage of traffic accidents occurring each day of the week. Assume that a sample of 420 acdldents provided the following data. Sunday Monday Tuesday Wednesday Thursday Friday Saturday 50 64 48 56 53 70 9 a. Conduct a hypothesis test to determine if the proportion of traffic accidents is the same for each day of the week. What is the p-value? Compute the value of the ?2 test statistic (to 3 decimals). The p-value is Select your snswer- Using a .05 level of significance, what is your conclusion? Select your answer the propartion of traffic accidents is nat the same for each day af the week b. Compute the percentage of traffic accidents occurring on each day of the week to 1 dedmal) Sunday Monday Tusday Wednesday Thursday Friday Saturday Percentage of traftic accidents, % What day has the highest percentage of traffic accidents? Does this seem reasonable? Discuss select you?.?. ?.? has he h ghest number o accidents, folov ed by Select Vuurana This mia es sense because hese are times when people go out and may be consuming alcohol, ha ng distractions such as more people r their car, and speedirig ? er

Answer 1

Ans:

	Observed(fo)	Expected(fe)	(fo-fe)^2/fe
Sunday	64	60	0.267
Monday	48	60	2.400
Tuesday	56	60	0.267
Wednesday	50	60	1.667
Thursday	53	60	0.817
Friday	70	60	1.667
Saturday	79	60	6.017
Total=	420	420	13.100

Test statistic:

Chi square=13.100

df=7-1=6

p-value=CHIDIST(13.100,6)=0.0415

As,p-value<0.05,we reject the null hypothesis,the proportion of traffic is not the same for each day of the week.

b)

	Observed(fo)	percentage
Sunday	64	15.2
Monday	48	11.4
Tuesday	56	13.3
Wednesday	50	11.9
Thursday	53	12.6
Friday	70	16.7
Saturday	79	18.8
Total=	420	100

Saturday has the highest percentage of traffic accidents.

Saturday has the highest number of accidents,followed by friday.