Question Question 1.1.(TCO A)An insurance company researcher con

04 Jun Question Question 1.1.(TCO A)An insurance company researcher con

Question
Question 1.1.(TCO A)An insurance company researcher conducted a survey on the number of car thefts in a large city for a period of 20 days last summer. The results are as follows.

3.1 4.2 2.0 3.5 2.6

5.3 3.5 3.1 2.6 3.3

4.7 3.7 3.0 2.6 4.0

3.8 4.4 3.2 3.2 3.8

a. Compute the mean, median, mode, and standard deviation, Q1, Q3, Min, and Maxfor the above sample data on number of car thefts.

b. In the context of this situation, interpret the Median, Q1, and Q3. (Points : 33)

Question 2.2.(TCO B) JR Trucking buys tires from three suppliers: Goodyear, Michelin, and Bridgestone. Data on the last 1,000 tires that were purchased are described in the table below.

Defective

Not Defective

Total

Goodyear

5

495

500

Michelin

6

294

300

Bridgestone

10

190

200

Total

21

979

1000

If you choose a tire at random, then find the probability that the tire

a. was made by Michelin.

b. was made by Goodyear and was defective.

c. was not defective, given that the tire was made by Bridgestone. (Points : 18)

Question 3.3.(TCO B)Welldale County officials claim that only 20% of homeowners are delinquent in the payment of property taxes. An investigative reporter selects a random sample of 25 homeowners in Welldale County. Assuming the officials are correct, find the probability that

a. at least 10 homeowners are delinquent in payment of property taxes.

b. fewer than five homeowners are delinquent in payment of property taxes.

c. exactly four homeowners are delinquent in payment of property taxes. (Points : 18)

Number of Trials=25; event probability: .20

Question 4.4.(TCO B) Telcom is a telephone answering service for physicians. The length of a message is a normally distributed variable with a mean 152.3 seconds and a standard deviation of 22.8 seconds.

a. What percentage of messages lasts longer than 120 seconds?

b. What percentage of messages lasts between 90 and 120 seconds?

c. Find the 95th percentile for length of message (i.e., find the cutoff for the longest 5% of messages). (Points : 18)

Question 5.5.(TCO C) A large-sized bag of Neato Chips should contain 16 oz of potato chips. A sample of 50 large-sized bags is selected with the following results.

Sample Size = 50

Sample Mean = 15.85 oz

Sample Standard Deviation = 1.53 oz

a. Construct a 95% confidence interval for the mean amount of contents per bag.

c. How large a sample size will need to be selected if we wish to have a 99% confidence interval with a margin for error of .10 oz? (Points : 18)

Question 6.6.(TCO C) The manufacturer of a certain brand of toothpaste claims that a high percentage of dentists recommend the use of their toothpaste. A random sample of 400 dentists results in 310 recommending their toothpaste.

a. Compute the 99% confidence interval for the population proportion of dentists who recommend the use of this toothpaste.

b. Interpret this confidence interval.

c. How large a sample size will need to be selected if we wish to have a 99% confidence interval that is accurate to within 3%? (Points : 18)

Question 7.7.(TCO D) A manufacturer of computer chips claims that less than 1% of his product fails to conform to specifications. In a random sample of 1,000 chips, eight are found to not conform to specifications. Does the sample data provide evidence to conclude that the percentage of chips that fail to conform to specifications is less than 1% (witha= .05)? Use the hypothesis testing procedure outlined below.

Question 8.8.(TCO D) A restaurant franchise company has a policy of opening new restaurants only in areas that have a mean household income in excess of $65,000. The company is currently considering an area to open a new restaurant. A random sample of 144 households from this area is selected yielding the following results.

Sample Size = 144

Sample Mean = $66,124

Sample Standard Deviation = $7,400

Does the sample data provide evidence to conclude that the population mean annual household income is in excess of $65,000 (usinga= .05)? Use the hypothesis testing procedure outlined below.

a. Formulate the null and alternative hypotheses.

c. Find the critical value (or values), and clearly show the rejection and nonrejection regions.

d. Compute the test statistic.

e. Decide whether you can reject Ho and accept Ha or not.

f. Explain and interpret your conclusion in part e. What does this mean?

g. Determine the observed p-value for the hypothesis test and interpret this value. What does this mean?

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h. Does the sample data provide evidence to conclude that the population mean annual household income is in excess of $65,000 (usinga= .05)? (Points : 24)

Question 9.(TCO E) At an auction, a national car rental agency sold 12 comparably equipped 3-year-old Chevrolet Corsicas. The data on mileage (X) and selling price (Y) are found below.

PRICE