1.	The following is the fuel economy data (in mpg, or "miles per gallon") for two types of gasoline tested in 13types of car.Assume that the data is normally distributed.
		Gasoline "A"	Gasoline "B"	Difference( "A" - "B" )
	Car # 1	35	34	1
	Car # 2	28	26.5	1.5
	Car # 3	32	30.5	1.5
	Car # 4	32	31.5	0.5
	Car # 5	36	35.5	0.5
	Car # 6	30	29	1
	Car # 7	37	35	2
	Car # 8	25	24	1
	Car # 9	23	23	0
	Car # 10	26	25	1
	Car # 11	30	30	0
	Car # 12	31	30.5	0.5
	Car # 13	35	34	1
	= 0.885
	How to get n? Just count the pairs! sd= 0.583
	Perform a hypothesis testat 95% confidence,to find out whetherGasoline "A" is different from Gasoline "B".Youshoulduse the paired (dependent) sample approach. To get full credit,do the following: 1.State your alternate and null hypotheses. 2.Show either your test statistic and p-value or your confidence interval. 3.State your conclusion: do you reject Ho? Are the mileages for the two types of gasoline different? YES or NO
2.	Using the same data as problem 1 create a confidence intervalat 95% confidencefor the difference between the sample means.
3.	A medical researcher is comparing the effectiveness of two treatments.Assume that the data is normally distributed.Sample data is as follows: TreatmentA: Time to recover = 8days s =2.5days n = 20 TreatmentB: Time to recover =11days s =3.5days n = 16 Ha: population means are not equal Ho: population means are equal Do not reject Ho Perform a hypothesis testat 95% confidenceto determine whetherthere is a significant difference in the time to recover between the two treatments.To get full credit, do the following: 1.State your alternate and null hypotheses. 2.Show either your test statistic and p-value or your confidence interval. 3.State your conclusion: do you reject Ho? Are the recovery times for the two treatments different? YESor NO
4	Two libraries are comparing their success rate at getting books returned on time. Sample data is as follows: Library A: n =200 books 180returned on time Library B: n =200 books 160returned on time Create a confidence interval at 95% confidence forthe difference between the proportion ofbooks returned at library A vs. the proportion of books returned at library B.
5	A researcher in aquaculture (fish farming) is interested in whether fish fed on minnows or fish raised on food pellets gain weight faster. A number of fish are randomly assigned to being fed minnows or food pellets.Assume that the data is normally distributed.Sample data is as follows: Sample A (minnows): Mean weight= 3.5lbs s= 0.5lbs. n = 25 Sample B (pellets): Mean weight= 2.9lbs s = 0.4 lbs n = 25 Perform a hypothesis testat 95% confidence,to determine whetherthe two populations grow at the same rate. To get full credit, do the following: 1.State your alternate and null hypotheses. 2.Show either your test statistic and p-value or your confidence interval. 3.State your conclusion: do you reject Ho? Are growth rates for the two types of feed different? YESor NO
6	A factory manager wanted to determine whether "Team A" vs. "Team B" made a different number of defective parts. A random sample of300 parts from each team showed the following sample data: Team A sample size n = 300 20parts are defective Team B sample size n = 300 30 parts are defective Perform a hypothesis testat the 95% confidence level,to determine whetherthe proportion of defective parts is different for "Team A" vs. "Team B"? To get full credit, do the following: 1.State your alternate and null hypotheses. 2.Show either your test statistic and p-value or your confidence interval. 3.State your conclusion: do you reject Ho? Are the defective parts rates for the two teams different? YESor NO
7.	The data below represents two paired samples. Using a paired data (dependent sample) approach, can you proveat 95% confidencethat the (population) mean difference is not zero? To get full credit, do the following: 1.State your alternate and null hypotheses. 2.Show either your test statistic and p-value or your confidence interval. 3.State your conclusion: do you reject Ho? Are the population means for the two samples different? YESor NO
		Sample 1	Sample 2	difference
	Data point 1	10	10	0
	Data point 2	10	11	-1
	Data point 3	11	12	-1
	Data point 4	12	12	0
	Data point 5	13	14	-1
	Data point 6	14	15	-1
	Data point 7	14	15	-1
	Data point 8	15	16	-1
	Data point 9	17	17	0
	Sample size is left for you to determine = -0.667 sd= 0.5
8	The following data is serum iron measured in the blood of a group of adult women. Serum iron is measured both before and after treatment. Perform a hypothesis test at 95% confidence to determine if the treatment makes a difference. Use a dependent (paired sample) approach. To get full credit, do the following: 1.State your alternate and null hypotheses. 2.Show either your test statistic and p-value or your confidence interval. 3.State your conclusion: do you reject Ho? Are the population means for the two samples different? YESor NO
	Assume data is normal.	After treatment	Before treatment	Difference = After - Before
	Sample size is left for you to	42	35	7
	determine.	55	40	15
		45	32	13
		48	46	2
		58	45	13
	Sample mean and sample	60	48	12
	standard deviation are	55	44	11
	provided but you should	50	40	10
	figure out n.	52	38	14
		50	45	5
			Mean =	1.2
			Standard dev =	4.237
			n =	?
9	Do a hypothesis test at 95% confidence to determine if the population means for the two samples below are different. To get full credit state your null and alternate hypothesis,show either test statistic and p-value or confidence interval, and state your conclusion: Do you reject Ho? (YES orNO) Couldthe population means be the same? YES or NO
	Sample A
	24.2	19.6	31.9	34.4	29.3	27.2	28.3	23.5	20.5	18.5
	24.4	23.7	23.1	26.4	29.3	28.4	18.3	29.1	23.8	24.7
	30.6	25.1	28	24.8	27.1	26.7	27.6	27.3	21.9	22.5
	27.2	27.8	22.9	19.6	26.1	21.3	22.5	27.3	24.8	26.9
	Sample B
	28.6	27.6	19	21.4	22.5	21.4	25.1	23.3	24.5	23.5
	33.2	27.2	29.3	26.4	21.9	21.5	25.1	20.6	27.9	25.7
	21	24.8	22.4	18	23.1	26.3	26.9	22.6	30.2	21.4

Sample means and standard deviations are provided but you should determine the sample size by counting the data.

Sample data for sample A:

Sample mean ==25.4 sample standard deviation = s =3.619 n =?

Sample data for sample B

Sample mean ==24.413 sample standard deviation =s =3.484 n =?

`