Question

1) In? 2003, an organization surveyed

1 comma 5081,508

adult Americans and asked about a certain? war, "Do you believe the United States made the right or wrong decision to use military? force?" Of the

1 comma 5081,508

adult Americans? surveyed,

1 comma 0861,086

stated the United States made the right decision. In? 2008, the organization asked the same question of

1 comma 5081,508

adult Americans and found that

570570

believed the United States made the right decision. Construct and interpret a? 90% confidence interval for the difference between the two population? proportions,

p 2003 minus p 2008p2003?p2008.

The lower bound of a? 90% confidence interval is

nothing.

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a? professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The

200200

students in group 1 had a mean score of

26.126.1

with a standard deviation of

4.84.8?,

while the

200200

students in group 2 had a mean score of

17.717.7

with a standard deviation of

3.93.9.

Complete parts ?(a) and ?(b) below.?(a) Determine the

9090?%

confidence interval for the difference in? scores,

mu 1 minus mu 2?1??2.

Interpret the interval.The lower bound is

nothing.

The upper bound is

nothing.

?(Round to three decimal places as? needed)

3)

Assume that both populations are normally distributed. ?(a) Test whether mu 1 not equals mu 2?1??2 at the alpha equals 0.01?=0.01 level of significance for the given sample data.?(b) Construct a 9999?% confidence interval about mu 1 minus mu 2?1??2.			Population 1	Population 2
		n	2020	2020
		x overbarx	19.219.2	20.420.4
		s	4.44.4	3.93.9

?(a) Test whether

mu 1 not equals mu 2?1??2

at the

alpha equals 0.01?=0.01

level of significance for the given sample data.

Determine the null and alternative hypothesis for this test.

A.

Upper H 0 :H0:mu 1 equals mu 2?1=?2

Upper H 1 :H1:mu 1 greater than mu 2?1>?2

B.

Upper H 0 :H0:mu 1 equals mu 2?1=?2

Upper H 1 :H1:mu 1 not equals mu 2?1??2

Your answer is correct.

C.

Upper H 0 :H0:mu 1 not equals mu 2?1??2

Upper H 1 :H1:mu 1 equals mu 2?1=?2

D.

Upper H 0 :H0:mu 1 not equals mu 2?1??2

Upper H 1 :H1:mu 1 greater than mu 2?1>?2

Detemine the? P-value for this hypothesis test.

Pequals=nothing

?(Round to three decimal places as? needed.)

Assume that both populations are normally distributed. ?a) Test whether mu 1 greater than mu 2?1>?2 at the alpha equals 0.05?=0.05 level of significance for the given sample data.?b) Construct a 9595?% confidence interval about mu 1 minus mu 2?1??2.			Sample 1	Sample 2
		n	2222	1515
		x overbarx	46.946.9	39.839.8
		s	7.37.3	10.610.6

LOADING...

Click the icon to view the Student? t-distribution table.

?a) Perform a hypothesis test. Determine the null and alternative hypotheses.

A.

Upper H 0H0?:

mu 1 equals mu 2?1=?2?,

Upper H 1H1?:

mu 1 greater than mu 2?1>?2Your answer is correct.

B.

Upper H 0H0?:

mu 1 less than mu 2?1<?2?,

Upper H 1H1?:

mu 1 greater than mu 2?1>?2

C.

Upper H 0H0?:

mu 1 greater than mu 2?1>?2?,

Upper H 1H1?:

mu 1 less than mu 2?1<?2

D.

Upper H 0H0?:

mu 1 equals mu 2?1=?2?,

Upper H 1H1?:

mu 1 less than mu 2?1<?2

Determine the test statistic.

tequals=nothing

?(Round to two decimal places as? needed.)

A researcher wanted to determine if carpeted or uncarpeted rooms contain more bacteria. The table shows the results for the number of bacteria per cubic foot for both types of rooms. A normal probability plot and boxplot indicate that the data are approximately normally distributed with no outliers. Do carpeted rooms have more bacteria than uncarpeted rooms at the alpha?equals=0.010.01 level of? significance?		Full data set
		Carpeted				Uncarpeted
		7.27.2	8.88.8	13.713.7		5.85.8	9.59.5	13.313.3
		6.46.4	13.513.5	7.27.2		13.413.4	12.312.3	5.65.6
		15.915.9	15.715.7			10.510.5	10.910.9

LOADING...

Click the icon to view the Student? t-distribution table.

What are the null and alternative? hypotheses?

Upper H 0H0?:

mu Subscript carpet?carpet

equals=

mu Subscript no carpet?no carpet

versus Upper H 1H1?:

mu Subscript carpet?carpet

greater than>

mu Subscript no carpet?no carpet

Calculate the test? statistic,

t 0t0.

t 0t0equals=nothing

?(Round to two decimal places as? needed.)

Answer 1

1)

	2003	2008
n	1508	1508
X	1086	570

90% Confidence interval: Z(0.10/2)= 1.645

Lower interval: 0.314183

Upper interval: 0.370167

2)

	Group 1	Group 2
n	200	200
Mean	26.1	17.7
S	4.8	3.9

90% confidence interval:

Pooled variance: