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Budget director wants to compare travel expense for sales

See attached file for clarity.

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 ( $ ) 129 135 148 160 135 144
Audit ( $ ) 125 110 132 134 142 123 133

Use the above data to answer the question

At the 0.05 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the
audit staff?

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

Reject H0 if t >

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

Pooled variance

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

Value of the test statistic

Problem Number 2
Bob Nale is the owner of Nale's Texaco GasTown. Bob would like to estimate the mean number of gallons of gasoline sold to his customers. Assume the number of gallons sold follows the normal distribution with a standard deviation of 3 gallons. From his records, he selects a random sample of 52 sales and finds the mean number of gallons sold is 8.05. (Round your answers to 2 decimal places.)

(a) The point estimate of the population mean is

(b) The 99 percent confidence interval for the population mean is between and


Solution Preview

Please see the attached files.

Answers 1
The test statistic is
Given α = 0.05
1) Reject H0 if t > 2.201
2) Pooled variance = 114.5952
3) Value of the test statistic = ...

Solution Summary

Budget director who wants to compare travel expenses for sales are examined.