Question

A​ case-control (or​ retrospective) study was conducted to investigate a relationship between the colors of helmets worn by motorcycle drivers and whether they are injured or killed in a crash. Results are given in the accompanying table. Using a 0.05 significance​ level, test the claim that injuries are independent of helmet color. Color of Helmet Black White Yellow Red Blue Controls​ (not injured) 469 363 33 152 75 Cases​ (injured or​ killed) 203 105 9 62 35 Click here to view the chi-square distribution table.LOADING...

Identify the null and alternative hypotheses.

Choose the correct answer below.

A. Upper H 0​: Injuries and helmet color are independent Upper H 1​: Injuries and helmet color are dependent

B. Upper H 0​: Injuries and helmet color are dependent Upper H 1​: Injuries and helmet color are independent

C. Upper H 0​: Color of helmet is independent of gender Upper H 1​: Color of helmet is dependent on gender

D. Upper H 0​: Whether a crash occurs and helmet color are dependent Upper H 1​: Whether a crash occurs and helmet color are independent

Compute the test statistic. ​(Round to three decimal places as​ needed.)

Find the critical​ value(s). ​(Round to three decimal places as needed. Use a comma to separate answers as​ needed.)

What is the conclusion based on the hypothesis​ test? Reject Fail to reject Upper H 0. There is is not sufficient evidence to warrant rejection of the claim that injuries are independent of helmet color.

Answer 1

A. H₀​: Injuries and helmet color are independent

H₁​: Injuries and helmet color are dependent

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Tabulated Statistics: C1, Worksheet columns

Rows: C1   Columns: Worksheet columns

	Black	White	Yellow	Red	Blue	All
not injured	469	363	33	152	75	1092
Expected count(E)	487.27	339.35	30.45	155.17	79.76
injured	203	105	9	62	35	414
Expected count	184.73	128.65	11.55	58.83	30.24
All	672	468	42	214	110	1506

Cell Contents
      Count
     

Chi-Square Test

	Chi-Square	DF	P-Value
Pearson	10.532	4	0.0324

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Reject Ho

is