1.Create a 95% confidence interval for the following sample data:

You obtain 260 successes in a sample of size n1=682 from the first population. You obtain 307 successes in a sample of size n2=768 from the second population.

What is the confidence interval for the difference of the two proportions? (Report answer accurate to two decimal places.)

(< p1p2 < )

2. Create a 99% confidence interval for the following sample data:

You obtain 151 successes in a sample of size n1=460 from the first population. You obtain 288 successes in a sample of size n2=720 from the second population. What is the confidence interval for the difference of the two proportions? (Report answer accurate to two decimal places.)

(

3. You wish to test the following claim (H1) at a significance level of =0.002.

Ho:1=2

H1:12

You believe both populations are normally distributed, but you do not know the standard deviations for either. You obtain a sample of size n1=20 with a mean of ^x1=53.3 and a standard deviation of s1=10.4 from the first population. You obtain a sample of size n2=10 with a mean of ^x2=56.7 and a standard deviation of s2=11.4 from the second population.

What is the test statistic for this sample? (Report answer accurate to 2 decimal places.)

test statistic = ()

What is the p-value for this sample? Report answer accurate to 4 decimal places.)

p-value = ()

4. Test the claim that the mean GPA of night students is significantly different than the mean GPA of day students at the 0.1 significance level.

The sample consisted of 35 night students, with a sample mean GPA of 2.32 and a standard deviation of 0.03, and 35 day students, with a sample mean GPA of 2.36 and a standard deviation of 0.05.

The test statistic is: ()(to 2 decimals)

The p-value is: ()(to 4 decimals)

5. You wish to test the following claim (H1) at a significance level of =0.02.

Ho:1=2

H1:1>2

You believe both populations are normally distributed, but you do not know the standard deviations for either. However, you also have no reason to believe the variances of the two populations are not equal. You obtain a sample of size n1=18 with a mean of ^x1=84.5 and a standard deviation of s1=15.3 from the first population. You obtain a sample of size n2=21 with a mean of ^x2=66.8 and a standard deviation of s2=17.2 from the second population.

What is the test statistic for this sample? (Report answer accurate to two decimal places.)

test statistic = ()

What is the p-value for this sample? (Report answer accurate to four decimal places.)

p-value = ()

6. Give a 98% confidence interval, for 12 given the following information.

n1=25, ^x1=2.95, s1=0.38

n2=45, ^x2=3.45, s2=0.3

( , ) Round to 2 decimal places.

7. Give a 99.8% confidence interval, for 12 given the following information.

n1=20, ^x1=2.65, s1=0.67

n2=30, ^x2=3.14, s2=0.71

( , ) Round to 2 decimal places.

8. You wish to test the following claim (H1) at a significance level of =0.002. For the context of this problem, d=21 where the first data set represents a pre-test and the second data set represents a post-test.

Ho:d=0

H1:d0

You believe the population of difference in scores is normally distributed, but you do not know the standard deviation. You obtain the following sample of data:

pre-test, post-test

34.2 36.8

39.5 19.4

47.9 46.1

51 52.6

48.9 38.6

41.3 45

29.6 20.3

41.1 28.4

44.5 47.4

41.7 23.2

37 24.3

37.6 35.1

43.5 32.8

38.4 27.7

27.7 39.7

51.6 42.6

What is the test statistic for this sample? (Report answer accurate to 2 decimal places.)

test statistic = ()

What is the p-value for this sample? (Report answer accurate to 4 decimal places.)

p-value = ()

9. You wish to test the following claim (H1) at a significance level of =0.002. For the context of this problem, d=21 where the first data set represents a pre-test and the second data set represents a post-test.

Ho:d=0

H1:d>0

You believe the population of difference in scores is normally distributed, but you do not know the standard deviation. You obtain the following sample of data:

pre-test, post-test

67.3 80.4

58.6 61

54.3 82.6

59.9 137.8

54.5 77.6

73.3 91.2

64.9 81.5

59.3 87.6

49.4 80.9

59.1 111.1

What is the test statistic for this sample? (Report answer accurate to 2 decimal places.)

test statistic = ( )

What is the p-value for this sample? (Report answer accurate to 4 decimal places.)

p-value = ()

10. You wish to test the following claim (H1) at a significance level of =0.002. For the context of this problem, d=21

where the first data set represents group 1 and the second data set represents group 2.

Ho:d=0

H1:d0

You believe the population of differences is normally distributed, but you do not know the standard deviation. You obtain the following sample of data:

Group 1, Group 2

20 21.7

19.8 26.9

30.1 4.4

26.8 19.9

19.6 -2.9

19.2 -6

31 2.8

19.4 6.5

What is the test statistic for this sample? (Report answer accurate to 2 decimal places.)

test statistic = ( )

What is the p-value for this sample? (Report answer accurate to 4 decimal places.)

p-value = ()