Question

A group of 908 elderly individuals were classified by race (White, Black) and by if they have been admitted to a hospital in the past 3.5 years (No, Yes).

Hospitalization	Race
		White	Black	Total
	No	313 Cell 11	361 Cell 12	674
	Yes	136 Cell 21	98 Cell 22	234
	Total	449	459	908

How many factorial combinations does the example above have?

2

4

6

9

more than 9

What percentage of all of the elderly individuals who have been admitted to a hospital in the past 3.5 years were Black?

50.55%

58.12%

41.88%

53.56%

10.79%

The expected frequency for Cell 12 falls within which range?

less than or equal to 289

290 to 309

310 to 329

330 to 349

greater than or equal to 350

Calculate the observed χ2 statistic for the association between race and being admitted to a hospital. Which interval does it fall within?

less than or equal to 8.9

9 to 9.9

10 to 10.9

11 to 11.9

greater than or equal to 12

Answer 1

1)  factorial combinations does the example above have =2² =4

2) percentage of all of the elderly individuals who have been admitted to a hospital in the past 3.5 years were Black =459/908=50.55%

3)

expected frequency for Cell 12 =row total*column total/grans total=459*674/908 =340.711

330 to 349

4)

applying chi square test:

Expected	Ei=Σrow*Σcolumn/Σtotal	White	Black	Total
	Yes	333.289	340.711	674
	No	115.711	118.289	234
	Total	449	459	908
chi square	=(Oi-Ei)2/Ei	White	Black	Total
	Yes	1.235	1.208	2.443
	No	3.557	3.480	7.037
	Total	4.792	4.688	9.480

interval for χ2 statistic 9 to 9.9