1. The owner of Limp Pines Resort wanted to know the average age of its clients. A random sample of 25 tourists is taken. It shows a mean age of 46 years with a standard deviation of 5 years. The width of a 98 percent confidence interval for the true mean client age is approximately :

A.2.492 years. B.2.326 years. C.2.797 years. D.1.711 years.

2. The owner of Torpid Oaks B&B wanted to know the average distance its guests had traveled. A random sample of 16 guests showed a mean distance of 85 miles with a standard deviation of 32 miles. The 90 percent confidence interval (in miles) for the mean is approximately

A.(74.3, 95.7)B.(68.7, 103.2) C.(71.8, 98.2) D.(71.0, 99.0)

3-1. Dullco Manufacturing claims that its alkaline batteries last at least 40 hours on average in a certain type of portable CD player. But tests on a random sample of 18 batteries from a day's large production run showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours. To test DullCo's hypothesis, the test statistic is

A.-1.960 B.?2.101 C.?1.728 D.?1.980

3-2. P-value ?

4. For tests of a mean, if other factors are held constant, which statement is correct?

A.A test statistic tcalc = 1.853 with n = 16 leads to rejection at ? = .05 in a one-tailed test.

B.It is harder to reject the null hypothesis in a two-tailed test rather than a one-tailed test.

C.If we desire ? = .10, then a p-value of .13 would lead us to reject the null hypothesis.

D.The critical value of Student's t increases as n increases.

5-1. A digital camcorder repair service has set a goal not to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed. A random sample of 12 repair records showed the following repair times (in days): 5, 7, 4, 6, 7, 5, 5, 6, 4, 4, 7, 5. H0: ? ? 5 days versus H1: ? > 5 days. At ? = .05, choose the right option.

A.Reject H0 if tcalc > 1.7960

B.Accept H0 if tcalc > 1.7960

C.Reject H0 if tcalc > 1.7960

D.Accept H0 if tcalc > 1.7960

5-2 the null hypothesis should be rejected and the goal is being met

A.FALSE, YESB.TRUE, NOC.FALSE, NOD.TRUE, YES

6. A coin was flipped 85 times and came up heads 55 times. At the .10 level of significance, chose the appropriate decision for whether the coin is biased toward heads? And is the true proportion greater than 0.50?

A.Reject H0 if z

B.Reject H0 if z

C.Reject H0 if z > 1.282; FALSE

D.Reject H0 if z > 1.282; TRUE

7. Faced with rising fax costs, a firm issued a guideline that transmissions of 10 or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 20 randomly chosen fax transmissions during the next year, yielding a sample mean of 11.88 with a standard deviation of 5.37 . At the .01 level of significance, is the true mean greater than 10?

8. The recent default rate on all student loans is 5.9 percent. In a recent random sample of 318 loans at private universities, there were 15 defaults. Does this sample show sufficient evidence that the private university loan default rate is below the rate for all universities, using a left-tailed test at ? = .010? Choose the appropriate hypothesis AND should the null hypothesis be rejected?

A.H0: ? .059; H1:

B.H0: ? .059; H1:

C.H0: ? .059; H1:

D.H0: ? .059; H1:

9. A regression model between sales (y in $1,000), unit price (x1 in dollars) and television advertisement (x2 in dollars) resulted in the following function:= 7 - 3x₁+ 5x₂

For this model SSR = 3500, SSE = 1500, and the sample size is 18.

The coefficient of the unit price indicates that if the unit price is:

A.inreased by $1 (holding advertising constant), sales are expected to increase by $3

B.increased by $1 (holding advertising constant), sales are expected to increase by $4,000

C.decreased by $1 (holding advertising constant), sales are expected to decrease by $3

D.increased by $1 (holding advertising constant), sales are expected to decrease by $3,000

10.A pharmaceutical company wants to answer the question whether it takes longer than 45 seconds for a drug in pill fonn to dissolve in the gastric juices of the stomach. A sample was taken from 8 patients taking the given drug in pill form and times for the pills to be dissolved were measured. The mean was 45.212 sec for the sample data with a standard error of 0.580. Determine the P-value for this test.

12-1. The Espresso Cart has had the following pattern of espresso sales over the last two weeks.What is the forecast for Friday's sales using a three-day moving average?

12-2. The Espresso Cart has had the following pattern of espresso sales over the last two weeks.What is the forecast for Friday's sales using a 3-day weighted moving average with weights of .5 (for newest), .3, and .2 (for oldest)?

13. Data from a small bookstore are shown in the table below, what is the slope and intercept? What percent of the variability in Sales is explained by the changes in the number of Sales People Working?

Number of sales people working Sales(in $1000) 2 11 3 12 5 17 6 18 10 18 10 20 12 21 15 24 17 25 21 25 average 10.1 19.1 st dev. 6.21 4.96 correlation coefficient: 0.945 Based on the above table, estimate the least squares line Sales = bo + b1 * Number of sales people