VIEWS: 928 PAGES: 9 POSTED ON: 4/9/2012
Page 1 26701093 15913752 1 rldbqn=1 False /main/CourseMod 1.(TCO 9) The hours of study and the final exam grades have this type of relationship: ŷ = 7.35(hours) + 34.62. Based on this linear regression equation, estimate the expected grade for a student spending 8 hours studying. Round your answer to two decimal places. (Points : 6) 58.80 82.25 91.97 93.42 0 1321066872 MultipleChoice 1 2.(TCO 5) Historical sales records show that 40% of all customers who enter a discount department store make a purchase. We are interested in calculating the probability that 3 of 5 customers make purchase. Choose the best answer of the following: (Points : 6) This is an example of a Poisson probability experiment This is an example of a Binomial probability experiment This is neither a Poisson nor a Binomial probability experiment Not enough information to determine the type of experiment 0 1321066874 MultipleChoice 4 3.(TCO 5) Microfracture knee surgery has a 75% chance of success on patients with degenerative knees. The surgery is performed on 5 patients. Find the probability of the surgery being successful on less than 3 patients? (Points : 6) 0.103516 0.632813 0.263672 0.087891 0 1321066876 MultipleChoice 8 (TCO 5) It has been recorded that 10 people get killed by shark attack every year. What is the 4. probability of having 5 or 6 people get killed by shark attack this year? (Points : 6) 0.130141 0.026484 0.100889 0.067086 0 1321066880 MultipleChoice 12 5. (TCO 2) The median teaching hours for a full time faculty at a state university is eight hours per week. What does this tell you about the typical teaching hours for full time faculty at that university? (Points : 6) Half of the full time faculties teach less than eight hours per week while half teaches more than eight hours per week. The average teaching hours for full time faculty is eight hours per week. More full time faculty teaches eight hours per week than any other number of teaching hours. The number of teaching hours for full time faculty in not very consistent because eight is such a low number. 0 1321066881 MultipleChoice 14 (TCO 6) Assuming that the data are normally distributed with a mean of 25 and a standard deviation of 6. 1.25, what is the z-score for a value of 27? (Points : 6) 2.30 1.60 3.10 -1.60 0 1321066884 MultipleChoice 16 7.(TCO 8) The mean hours of Internet usage by adults in the US in claimed to be 25 hours per week. A hypothesis test is performed at a level of significance of 0.05 with a P-value of 0.01. Choose the best interpretation of the hypothesis test. (Points : 6) Reject the null hypothesis; there is enough evidence to reject the claim that the mean of hours Internet usage by adults in the US is 25 hours per week. Reject the null hypothesis; there is enough evidence to support the claim that the mean hours Internet usage by adults in the US is 25 hours per week. Fail to reject the null hypothesis; there is not enough evidence to reject the claim that the mean hours of Internet usage by adults in the US is 25 hours per week. Fail to reject the null hypothesis; there is not enough evidence to support the claim that the mean hours of Internet usage by adults in the US is 25 hours per week.. 0 1321066889 MultipleChoice 20 8.(TCO 8) A result of an entry level exam reveals that 22% of students fail that exam. In a hypothesis test conducted at a level of significance of 2%, a P-value of 0.045 was obtained. Choose the best interpretation of the hypothesis test. (Points : 6) Fail to reject the null hypothesis; there is not enough evidence to reject the claim that 22% of students fail the entry level exam. Fail to reject the null hypothesis; there is not enough evidence to support the claim that 22% of students fail the entry level exam. Reject the null hypothesis; there is enough evidence to reject the claim that 22% of students fail the entry level exam. Reject the null hypothesis; there is enough evidence to support the claim that 22% of students fail the entry level exam. 0 1321066891 MultipleChoice 22 9.(TCO 2) You want to buy light bulbs and you want to choose between two vendors. Vendor A’s light bulbs have a mean life time of 800 hours and a standard deviation of 175 hours. Vendor B’s light bulbs also have a mean life time of 800 hours, but a standard deviation of 225 hours. You want light bulbs that have more life time consistency, which vendor will you purchase from? (Points : 6) Vendor A because you will be more likely get light bulbs with the same life time Vendor B because you will be more likely get light bulbs with the same life time Either one because both produce light bulbs with the same mean life time. Neither one because a mean height of 800 inches is too short for a light bulb. 0 1321066895 MultipleChoice 25 (TCO 4) A jar contains balls of four different colors; red, blue, yellow and green. The total balls are 10. divides as 45% red, 35% blue, 15% yellow, and 5% green. If you are to select one ball at random. Find the expected value of your winning amount if the payments are set to be $5, $15, $25, $60 for red, blue, yellow and green ball respectively. Winning 5 15 25 60 amount Probability 45% 35% 15% 5% (Points : 6) The expected winning amount is $28.50 The expected winning amount is $14.25 The expected winning amount is $25.50 The expected winning amount is $11.25 0 1321066897 MultipleChoice 29 (TCO 3) The grades of 20 students are listed below. Use the stem & leaf to determine the shape of 11. the distribution. Choose the best answer. 4|4 5|68 6|579 7|157889 8|3457889 9|7 (Points : 6) The data is symmetric The data is skewed to the right The data is skewed to the left The data is bimodal 0 1321066899 MultipleChoice 53 12. (TCO 1) A researcher is considering using 90% confidence interval for his research project instead of 95%. What happens to the required sample size if the confidence level is decreased from 95% to 90% and the same error margin is allowed in each case? (Points : 6) The sample size remains unchanged The sample size needs to increase The sample size needs to decrease Not enough information is provided to draw a conclusion regarding the sample size in this case. 0 1321066900 MultipleChoice 36 (TCO 6) Horse race time is found to be normally distributed with a mean value of 10 minutes and a 13. standard deviation of 2 minutes. Horses whose race time is in the top 5% will not be eligible to participate in a second round. What is the lowers race time that makes a horse losses his eligibility to participate in a second round? (Points : 6) 13.29 12 6.71 15.29 0 1321066902 MultipleChoice 37 (TCO 5) A class containing 20 students 8 of them are females. In how many ways can we select a 14. group of 5 male students? (Points : 6) 56 792 6720 95040 0 1321066904 MultipleChoice 41 15.(TCO 6) Research shows that the life time of Everlast automobile tires is normally distributed with a mean value of 60,000 miles and a standard deviation of 5,000 miles. What is the probability of having a tire that lasts more than 67,000 miles? (Points : 6) 0.9192 0.0808 1.40 0.0793 0 1321066906 MultipleChoice 45 (TCO 10) A research shows that employee salaries at company XYX, in thousands of dollars, are 16. given by the equation y-hat= 48.5 + 2.2 a + 1.5 b where ‘a’ is the years of experience, and ‘b’ is the education level in years. In thousands of dollars, predict the salary for an employee with 5 years experience and 16 years education level. (Points : 6) 52.5 59.5 83.5 69.5 0 1321066908 MultipleChoice 46 (TCO 9) For the graph below, choose the statement that best describes the relationship between the 17. variables. (Points : 6) As hours of absences increases, grades decreases. As hours of absences decreases, grades increases. As hours of absences increases, grades increases. There is no relationship between hours of absences and grades. page 2 26701096 15913752 2 rldbqn=1 False /main/CourseMod (TCO 8) For the following statement, write the null hypothesis and the alternative hypothesis. Also label 1. which one is the claim. A car manufacturer claims that their cars makes at least 35 miles per gallon of fuel. (Points : 8) 0 1321066912 Short 11 2.(TCO 11) A pizza restaurant manager claims that the average home delivery time for their pizza is no more than 20 minutes. A random sample of 49 home delivery pizzas was collected. The sample mean was found to be 21.25 minutes and the standard deviation was found to be 4.3 minutes. Is there evidence to reject the manager’s claim at alpha =.01? Perform an appropriate hypothesis test, showing the necessary calculations and/or explaining the process used to obtain the results. (Points : 20) 0 1321066913 Essay 126 3.(TCO 5) A multiple choice exam contains 50 questions. Each question has 5 choices, one of which is correct. We are interested in knowing the probability guessing exactly 18 questions correctly. (a) Is this a binomial experiment? Explain how you know. (b) Use the correct formula to find the probability of guessing exactly 18 questions correctly out of the 50 questions. Show your calculations or explain how you found the probability. (Points : 20) 0 1321066915 Essay 101 4.(TCO 6) The monthly utility bills are normally distributed with a mean value of $160 and a standard deviation of $25. (a) Find the probability of having a utility bill between 120 and 180. (b) Find the probability of having a utility bill less than $120. (c) Find the probability of having a utility bill more than $210. (Points : 20) 0 1321066916 Essay 52 5.(TCO 8) A Mall manager claims that in average every customer spends $37 per a single visit to the mall. To test this claim, you took a sample of 64 customers and found the sample mean to be $34 and the sample standard deviation to be $5. At alpha = 0.05, test the Mall’s manager claim. Perform an appropriate hypothesis test, showing the necessary calculations and/or explaining the process used to obtain the results. (Points : 20) 0 1321066917 Essay 124 6.(TCO 7) A bank manager wanted to estimate the mean number of transactions businesses make per month. For a sample of 60 businesses, he found the mean number of transaction per month to be 38 and the standard deviation to be 8.5 transactions. (a) Find a 95% confidence interval for the mean number of business transactions per month. Show your calculations and/or explain the process used to obtain the interval. (b) Interpret this confidence interval and write a sentence that explains it. (Points : 20) 0 1321066919 Essay 110 7.(TCO 7) A company’s CEO wanted to estimate the percentage of defective product per shipment. In a sample containing 400 products, he found 25 defective products. (a) Find a 95% confidence interval for the true proportion of defective product. Show your calculations and/or explain the process used to obtain the interval. (b) Interpret this confidence interval and write a sentence that explains it. (Points : 20) 0 1321066920 Essay 113 8.(TCO 2) The ages of 10 students are listed in years: {17,22,19,24,21,23,29,18,22,28 } (a) Find the mean, median, mode, sample variance, and range. (b) Do you think that this sample might have come from a normal population? Why or why not? (Points : 20)