1. A guidance counselor wishes to determine if the proportion of high school girls in his school district who have jobs are equal to the national average. He surveys 80 female students, ages 16 through 18, to determine if they work or not. The results are shown:

	16-year-olds	17-year-olds	18-year-olds
Work	45	31	38
Don't work	35	49	42

With = 0.01, can the researcher claim that the proportions of the girls who work are equal?

2. Class sizes were noted for a random sample of classes at 3 levels for a large school district. At =0.01, can it be concluded that there is a difference in the mean class size at the three different levels? If a difference exists, test each pair of means to locate the difference.

Elementary	Middle School	Secondary School
30	24	20
28	27	18
25	30	24
26	25	20
28	26	23
32	28	24
24		24
29

3. A recent survey asked adults nationwide if they thought that the federal government should continue to fund Nasa's efforts to send unstaffed missions to Mars. 56% said they should continue, 40% said they should not continue, and 4% had no opinion. A random sample of 200 college students resulted in these numbers:

Should continue: 126

Should not continue: 65

No opinion: 9

Is there sufficient evidence at @= 0.05 to conclude that the opinions of the college students differ from those of the report?

4. Are health and happiness related? The following data represents the level of happiness and level of health for a random sample of individuals from a General Social Survey.

			Health
		Excellent	Good	Fair	Poor
Happiness	Very Happy	271	261	82	20
	Pretty Happy	247	567	231	53
	Not too Happy	33	103	92	36

Can you conclude that health and happiness are related? Use @(alfa)=0.05

5. ) The times required by 3 workers to perform an assembly -line task were recorded on five randomly selected occasions. Here are the times, to the nearest minute.

Hank	Susan	Joseph
8	8	10
10	9	9
9	9	10
11	8	11
10	10	9

Are the three means equal for @(alfa)=0.05 ?