UMUC STAT 230 Final Exam Spring 2013
STAT 230 Last Examination UMUC Spring 2013 100 Factors --------------------------------------------------------------------------------------------------------------------- Use the data beneath to reply Questions 1 by four. Given a pattern measurement of 36, with pattern imply 670.three and pattern normal deviation 114.9, we carry out the next speculation take a look at. Null Speculation Different Speculation 1. What is the take a look at statistic? 2. At a 10% significance degree (90% confidence degree), what's the vital worth in this take a look at? Will we reject the null speculation? three. What are the border values between acceptance and rejection of this speculation? four. What is the ability of this take a look at if the assumed true imply had been 710 as a substitute of 700? Questions 5 by eight contain rolling of cube. 5. Given a good, six-sided die, what's the likelihood of rolling the die twice and getting a “1” every time? 6. What is the likelihood of getting a “1” on the second roll once you get a “1” on the primary roll? 7. The Home managed to load the die in such a method that the faces “2” and “4” present up twice as continuously as all different faces. In the meantime, all the opposite faces nonetheless present up with equal frequency. What's the likelihood of getting a “1” when rolling this loaded die? eight. Write the likelihood distribution for this loaded die, displaying every final result and its likelihood. Additionally plot a histogram to present the likelihood distribution. Use the information within the desk to reply Questions 9 by 11. x three 1 four four 5 y 1 -2 three 5 9 9. Decide SSxx, SSxy, and SSyy. 10. Discover the equation of the regression line. What's the predicted worth when 11. Is the correlation important at 1% significance degree (99% confidence degree)? Why or why not? Use the information beneath to reply Questions 12 by 14. A group of scholars from three universities had been requested to choose their favourite school sport to attend of their alternative: The outcomes, in variety of college students, are listed as follows: Soccer Basketball Soccer Whole Maryland 60 70 20 150 Duke 10 75 15 100 UCLA 35 65 25 125 Whole 105 210 60 375 Supposed a pupil is randomly chosen from the group talked about above. 12. What is the likelihood that the coed is from UCLA or chooses soccer? 13. What is the likelihood that the coed is from Duke, on condition that the coed chooses basketball? 14. What is the likelihood that the coed is fromMaryland and chooses soccer? Use the data beneath to reply Questions 15 and 17. There are 3600 apples in a cargo. The weight of the apples on this cargo is often distributed. It's discovered that it a imply weight of 14 ounces with a normal deviation of two.5 ounces. 15. How a lot of apples have weights between 13 ounces and 15 ounces? 16. What is the likelihood randomly chosen mango weighs lower than 12.5 ounces? 17. A high quality inspector randomly chosen 100 apples from the cargo. a. What is the likelihood that the 100 randomly chosen apples have a imply weight lower than 12.5 ounces? b. Do you give you the identical end in Query 16? Why or why not? 18. A pharmaceutical firm has developed a screening take a look at for a uncommon illness that troubled 2% of the inhabitants. Sadly, the reliability of this take a look at is just 80%, which suggests that 20% of the examined will get a false optimistic. If a topic is examined optimistic based mostly on this take a look at, what's the likelihood that he has the illness? Use the data beneath to reply Questions 19 and 20. Benford's regulation, additionally referred to as thefirst-digit regulation, states that in lists of numbers from many (however not all) real-life sources of knowledge, the main digit is distributed in a particular, non-uniform method proven within the following desk. Main Digit 1 2 three four 5 6 7 eight 9 Distribution of Main Digit (%) 30.1 17.6 12.5 9.7 7.9 6.7 5.eight 5.1 four.6 The proprietor of a small enterprise want to audit its account payable over the previous 12 months due to a suspicion of fraudulent actions. He suspects that considered one of his managers is issuing checks to non-existing distributors to be able to pocket the cash. There have been 790 checks written out to distributors by this supervisor. The main digits of those checks are listed as comply with: Main Digits 50 15 12 74 426 170 11 23 9 19. Suppose you're employed as a forensic accountant by the proprietor of this small enterprise, what statistical take a look at would you use to decide if there may be fraud dedicated within the issuing of checks? What's the take a look at statistic on this case? Hardness of Gem – Questions 23 and 24 Listedbelow are measured hardness indices from three totally different collections of gem stones. Assortment Hardness Indices A 9.three 9.three 9.three eight.6 eight.7 9.three 9.three -- --- --- --- --- --- 9.91 zero.10 B eight.7 7.7 7.7 eight.7 eight.2 7.four --- --- --- --- --- eight.03 zero.60 C 7.2 7.9 6.eight 7.four 6.5 6.6 6.7 6.5 6.5 7.1 6.7 5.5 7.three 6.82 zero.34 You might be additionally on condition that . 20. What is the take a look at statistic? 21. Use a 5% significance degree (95% confidence degree) to check the declare that the totally different collections have the identical imply hardness. 22. A couple has three daughters. The spouse is anticipating one other child. a. What is the likelihood that the brand new child is a lady once more? b. Suppose the brand new child seems to be a lady. What is the likelihood household with four kids which might be all women? Use the information beneath to reply Questions 26 and 27. This is a abstract of the midterm scores for 2 sections of STAT 230. The midterm questions and the grading standards are totally different in these two sections. Part A Pupil Rating Part B Pupil Rating A 70 H 15 B 42 I 57 C 53 J 48 D 61 Ok 90 E 22 L 85 F 85 M 73 G 59 N 49 ----- ------ O 39 23. What are the imply and normal deviation of the scores in Part A? 24. We discover that StudentF in Part A and StudentL in Part B have the identical numerical rating. a. How do they stand relative to their very own lessons? 25. Peter, Paul, Mary, Andrew, John, and Martha are members of the pastoral council at a native church. They're to be seated at one facet of an extended convention desk in a pastoral council assembly. a. How many potential methods can these 6 council members will be seated? b. How many potential sitting preparations are there if solely gender is taken into account in the method? 26. A banquet organizer is aware of that not all 600 invited friends will present up at an occasion. Primarily based on previous expertise, solely 80% of the invited visitor for this particular occasion will come. When costly dishes are served, it could be prudent to not order the complete 600 plates as a result of a very good variety of them will probably be wasted. Then again, the banquet organizer will attempt to keep inside 7% likelihood that he wouldn't need to rush to organize the costly dishes. How many of those costly dishes would you order if you happen to had been organizing this banquet?