The null and alternate hypotheses are:

H₀ : ₁ = ₂

H₁ : _{1 2}

1.A random sample of 11 observations from one population revealed a sample mean of 23 and a sample standard deviation of 4.6. A random sample of 8 observations from another population revealed a sample mean of 28 and a sample standard deviation of 3.6.

The population standard deviations are unknown but assumed to be equal. At the 0.05 significance level, is there a difference between the population means?

a. State the decision rule. (Negative amounts should be indicated by a minus sign. Round your answer to 3 decimal places.)

? Compute the pooled estimate of the population variance. (Round your answer to 3 decimal places.)

Pooled estimate of the population variance=

2.Ms. Lisa Monnin is the budget director for Nexus Media Inc. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.

Sales ($) 129 133 147 159 138 143

Audit ($) 124 102 126 140 146 105 139

The population standard deviations are unknown but assumed to be equal. At the 0.100 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff?>

a. State the decision rule. (Round your answer to 3 decimal places.)

Reject H₀ if t >_________.

b. Compute the pooled estimate of the population variance. (Round your answer to 2 decimal places.)

Pooled variance________.

c. Compute the test statistic. (Round your answer to 3 decimal places.)

Value of the test statistic________.

3.The null and alternate hypotheses are:

H₀ : _d 0

H₁ : _d > 0

The following sample information shows the number of defective units produced on the day shift and the afternoon shift for a sample of 4 days last month.

Day

1 2 3 4

Day shift 10 10 16 17

Afternoon shift 9 10 14 15

At the .05 significance level, is there a difference in the mean number of citations given by the two shifts?

a. What is the p-value?NOTE: P-value calculators are available through online search. (Round your answer to 4 decimal places.)

? p-value_______

4.The manufacturer of an MP3 player wanted to know whether a 10% reduction in price is enough to increase the sales of its product. To investigate, the owner randomly selected eight outlets and sold the MP3 player at the reduced price. At seven randomly selected outlets, the MP3 player was sold at the regular price. Reported below is the number of units sold last month at the regular and reduced prices at the randomly selected outlets.

Regular price 139 129 96 123 149 133 97

Reduced price 139 129 96 123 149 133 97 132

At the .01 significance level, can the manufacturer conclude that the price reduction resulted in an increase in sales?

a. Compute the test statistic. (Round your answers to 2 decimal places.)

?Test statistic______

b. Compute the p-value.NOTE: P-value calculators are available through online search. (Round your answer to 4 decimal places.)

?p-value_______

5.Fairfield Homes is developing two parcels near Pigeon Fork, Tennessee. In order to test different advertising approaches, it uses different media to reach potential buyers. The mean annual family income for 13 people making inquiries at the first development is $148,000, with a standard deviation of $36,000. A corresponding sample of 24 people at the second development had a mean of $185,000, with a standard deviation of $34,000. Assume the population standard deviations are the same. At the 0.05 significance level, can Fairfield conclude that the population means are different?

At the 0.05 significance level, can Fairfield conclude that the population means are different?

a. Compute the p-value.NOTE: P-value calculators are available through online search. (Round your answer to 4 decimal places.)

?p-value________