1. In a hypothesis test involving a population mean, which of the following would be an acceptable formulation?

H0: $1,700

Ha:> $1,700

H0: $1,700

Ha:> $1,700

H0:> $1,700

Ha: $1,700

None of the above is a correct formulation.

2. How much money does the average professional football fan spend on food at a single football game? That question was posed to 10 randomly selected football fans. The sample results provided a sample mean and standard deviation of $12.00 and $3.45, respectively. Use this information to construct a 90% confidence interval for the mean. Hint: Use Excel to calculate thet*n-1value.

12 1.796(3.45/)

12 1.833(3.45/)

12 1.383(3.45/)

12 1.812(3.45/)

3. Researchers have claimed that the average number of headaches per student during a semester of Business Statistics is 11. Statistics students believe the average is higher. In a sample ofn= 23 students the mean is 16 headaches with a deviation of 1.8. Which of the following represent the null and alternative hypotheses necessary to test the students' belief?

H₀:< 11 vs.H_a:= 11

H₀:= 11 vs.H_a:> 11

H₀:= 11 vs.H_a:< 11

H₀:= 11 vs.H_a: 11

4. What type of car is more popular among college students, American or foreign? One hundred fifty-nine college students were randomly sampled and each was asked which type of car he or she prefers. A computer package was used to generate the printout below of a 95% confidence interval for the proportion of college students who prefer American automobiles.

SAMPLE PROPORTION = .396

SAMPLE SIZE = 159

UPPER LIMIT = .472

LOWER LIMIT = .320

Which of the following is a correct practical interpretation of the interval?

We are 95% confident that the proportion of all college students who prefer foreign cars falls betweenand.

We are 95% confident that the proportion of the 159 sampled students who prefer American cars falls betweenand.

We are 95% confident that the proportion of all college students who prefer American cars falls betweenand.

95% of all college students prefer American cars betweenandof the time.

5. Private colleges and universities rely on money contributed by individuals and corporations for their operating expenses. Much of this money is invested in a fund called an endowment, and the college spends only the interest earned by the fund. A recent survey of eight private colleges in the United States revealed the following endowments (in millions of dollars): 60.2, 47.0, 235.1, 490.0, 122.6, 177.5, 95.4, and 220.0. Summary statistics yieldandCalculate a 99% confidence interval for the mean endowment of all private colleges in the United States. Hint:: Use t-Confidence Interval for a Mean spreadsheet.

180.975 181.387

180.975 189.173

180.975 169.672

180.975 176.979

6. What type of car is more popular among college students, American or foreign? One hundred fifty-nine college students were randomly sampled and each was asked which type of car he or she prefers. A computer package was used to generate the printout below for the proportion of college students who prefer American automobiles.

SAMPLE PROPORTION = .398455

SAMPLE SIZE = 159

UPPER LIMIT = .464240

LOWER LIMIT = .331153

What proportion of the sampled students prefer foreign automobiles?

.398455

.601545

.464240

.331153

7. An industrial supplier has shipped a truckload of teflon lubricant cartridges to an aerospace customer. The customer has been assured that the mean weight of these cartridges is in excess of the 14 ounces printed on each cartridge. To check this claim, a sample ofcartridges are randomly selected from the shipment and carefully weighed. Summary statistics for the sample are:To determine whether the supplier's claim is true, consider the test, 14," style="box-sizing: border-box; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); border: 0px; max-width: 100%; height: auto; display: inline; vertical-align: middle; line-height: inherit; max-height: 31.25rem;">where is the true mean weight of the cartridges. Calculate the p-value.

-1.7207

-2.0796

0.0183

0.0092

8. Assuming that the change in daily closing prices for stocks on the New York Stock Exchange is a random variable that is normally distributed with a mean of $.35 and a standard deviation of $.33. Based on this information, what is the probability that a randomly selected stock will close up $.75 or more? Remember to draw a picture so that you know which area under the curve we are interested in finding.

0.710

0.386

0.113

0.886

9. Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

n = 46; Arithmetic Mean= 28.00; Standard Deviation = 25.92; Standard Error = 3.82;

Null Hypothesis:H₀: =20; H_a: >20; =0.10; df = 45;TTest Statistic = 2.09;

One-Tail Test Upper Critical Value = 1.3006;p-value = 0.021

True or False: The null hypothesis would be rejected.

10. Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:

n = 46; Arithmetic Mean= 28.00; Standard Deviation = 25.92; Standard Error = 3.82;

Null Hypothesis:H₀: =20; H_a: >20; =0.10; df = 45;TTest Statistic = 2.09;

One-Tail Test Upper Critical Value = 1.3006;p-value = 0.021

The parameter the manager is interested in is

the mean number of defective light bulbs per case among the 46 cases.

the mean number of defective light bulbs per case produced during the morning shift.

the proportion of cases with defective light bulbs produced at the plant.

the mean number of defective light bulbs per case produced at the plant.