Question

A highway department executive claims that the number of fatal accidents which occur in her state does not vary from month to month. The results of a study of 171 fatal accidents were recorded. Is there enough evidence to reject the highway department executive's claim about the distribution of fatal accidents between each month? Month Fatal Accidents Jan 13 Feb Mar 11 16 Apr May Jun 12 14 21 Jul 11 Aug 7 Sep 11 Oct 10 Nov 23 Dec 22 Copy Data Step 1 of 10: State the null and alternative hypothesis. Answer Answered 2 Points Keypad Ho: Number of fatal accidents does not vary from month to month. H: Number of fatal accidents does vary from month to month. Ho: Number of fatal accidents does vary from month to month. H: Number of fatal accidents does not vary from month to month.

Answer 1

Ho: Number of fatal accidents does not vary from month to month. °H: Number of fatal accidents does vary from month to month. The proportions of fatal accidents during each month are all thought to be equal. E(. ) = 12 – 14.25 Ecomax) = 12 – 14.25 TestStatistic z?=? (: - E) 20.649 Degrees of freedom-12-1=11. Because there are 12 months Critical value = 3.816 Reject Null hypothesis since Test statistic is > critical value There is enough evidence to reject the claim that the number of fatal accidents does not vary from month to month.

Month	Oi	Ei	(Oi-Ei)^2/Ei
jan	13	14.25	0.109649
feb	11	14.25	0.741228
mar	16	14.25	0.214912
april	12	14.25	0.355263
may	14	14.25	0.004386
june	21	14.25	3.197368
july	11	14.25	0.741228
aug	7	14.25	3.688596
sept	11	14.25	0.741228
oct	10	14.25	1.267544
nov	23	14.25	5.372807
dec	22	14.25	4.214912
	171	171	20.64912
Test statistic	20.64912
Critical value	3.815748

A в D 1 Month 2 jan 3 feb 4 mar 5 april 6 may 7 june 8 july 9 aug sept oct 12 nov 13 dec 14 15 16 Test statistic 17 Critical value =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =171/12 =SUM(C2:C13) (Oi-Ei)^2/Ei =POWER(B2-C2,2)/C2 =POWER(B3-C3,2)/C3 =POWER(B4-C4,2)/C4 =POWER(B5-C5,2)/C5 =POWER(B6-C6,2)/C6 =POWER(B7-C7,2)/C7 =POWER(B8-C8,2)/C8 =POWER(B9-C9,2)/C9 =POWER(B10-C10,2)/C10 =POWER(B11-C11,2)/C11 =POWER(B12-C12,2)/C12 =POWER(B13-C13,2)/C13 =SUM(D2:013) =SUM(B2:B13) =D14 =CHIINV(1-0.05/2,11