1.The sample consisted of 70 night students, with a sample mean GPA of 2.82 and a standard deviation of 0.04, and 55 day students, with a sample mean GPA of 2.84 and a standard deviation of 0.03.

The test statistic is: (to 2 decimals)

The critical value is:

2.Test the claim that the mean GPA of night students is smaller than the mean GPA of day students at the .01 significance level.

The null and alternative hypothesis would be:

H

0

:

N

=

D

H0:N=D

H

1

:

N

D

H1:ND

H

0

:

N

=

D

H0:N=D

H

1

:

N

>

D

H1:N>D

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

p

D

H1:pNpD

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

<

p

D

H1:pN

H

0

:

N

=

D

H0:N=D

H

1

:

N

<

D

H1:N

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

>

p

D

H1:pN>pD

Incorrect

The test is:

two-tailed

right-tailed

left-tailed

Incorrect

The sample consisted of 70 night students, with a sample mean GPA of 2.22 and a standard deviation of 0.05, and 30 day students, with a sample mean GPA of 2.25 and a standard deviation of 0.06.

The test statistic is:(to 2 decimals)

The critical value is:(to 2 decimals)

Based on this we:

• Fail to reject the null hypothesis
• Reject the null hypothesis

3.Test the claim that the mean GPA of night students is larger than the mean GPA of day students at the .05 significance level.

The null and alternative hypothesis would be:

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

>

p

D

H1:pN>pD

H

0

:

N

=

D

H0:N=D

H

1

:

N

<

D

H1:N

H

0

:

N

=

D

H0:N=D

H

1

:

N

D

H1:ND

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

p

D

H1:pNpD

H

0

:

N

=

D

H0:N=D

H

1

:

N

>

D

H1:N>D

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

<

p

D

H1:pN

The test is:

left-tailed

right-tailed

two-tailed

3.Test the claim that the mean GPA of night students is larger than the mean GPA of day students at the .05 significance level.

The null and alternative hypothesis would be:

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

>

p

D

H1:pN>pD

H

0

:

N

=

D

H0:N=D

H

1

:

N

<

D

H1:N

H

0

:

N

=

D

H0:N=D

H

1

:

N

D

H1:ND

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

p

D

H1:pNpD

H

0

:

N

=

D

H0:N=D

H

1

:

N

>

D

H1:N>D

H

0

:

p

N

=

p

D

H0:pN=pD

H

1

:

p

N

<

p

D

H1:pN

The test is:

left-tailed

right-tailed

two-tailed

The sample consisted of 75 night students, with a sample mean GPA of 2.97 and a standard deviation of 0.07, and 45 day students, with a sample mean GPA of 2.96 and a standard deviation of 0.03.

The test statistic is:(to 2 decimals)

The critical value is:(to 2 decimals)

Based on this we:

• Fail to reject the null hypothesis
• Reject the null hypothesis

4.A leading magazine (like Barron's) reported at one time that the average number of weeks an individual is unemployed is 26 weeks. Assume that for the population of all unemployed individuals the population mean length of unemployment is 26 weeks and that the population standard deviation is 2.2 weeks. Suppose you would like to select a random sample of 98 unemployed individuals for a follow-up study.

Find the probability that a single randomly selected value is greater than 26.4.

P(X> 26.4) =(Enter your answers as numbers accurate to 4 decimal places.)

Find the probability that a sample of sizen

=

98

n=98

is randomly selected with a mean greater than 26.4.

P(M> 26.4) =(Enter your answers as numbers accurate to 4 decimal places.)

5.The lengths of pregnancies in a small rural village are normally distributed with a mean of 269 days and a standard deviation of 12 days.

In what range would you expect to find the middle 95% of most pregnancies?

Betweenand.

If you were to draw samples of size 44 from this population, in what range would you expect to find the middle 95% of most averages for the lengths of pregnancies in the sample?

Betweenand.

Enter your answers as numbers. Your answers should be accurate to 1 decimal places.