Ch8 Test Bank

b. The likelihood for any individual estimation of a constant irregular variable is zero, yet for discrete arbitrary factors it isn't. c. Likelihood for ceaseless arbitrary factors implies finding the zone under a bend, while for discrete irregular factors it implies adding singular probabilities. d. These decisions are valid. ANS:DPTS:1REF:SECTION 8. 1 2. Which of coming up next is in every case valid for all likelihood thickness elements of nonstop irregular factors? a. The likelihood at any single point is zero. b. They contain an uncountable number of potential qualities. c. The absolute zone under the thickness work f(x) rises to 1. d. These decisions are valid. ANS:DPTS:1REF:SECTION 8. 1 3. Assume f(x) = 0. 25. What scope of potential qualities would x be able to take on and still have the thickness work be genuine? a. [0, 4] b. [4, 8] c. [? 2, +2] d. These decisions are valid. ANS:DPTS:1REF:SECTION 8. 1 4. The likelihood thickness work, f(x), for any persistent irregular variable X, speaks to: a. ll potential qualities that X will expect inside some span a ? x ? b. b. the likelihood that X takes on a particular worth x. c. the stature of the thickness work at x. d. None of these decisions. ANS:CPTS:1REF:SECTION 8. 1 5. Which of coming up next is valid about f(x) when X has a uniform circulation over the span [a, b]? a. The estim ations of f(x) are distinctive for different estimations of the irregular variable X. b. f(x) approaches one for every conceivable estimation of X. c. f(x) rises to one isolated by the length of the span from a to b. d. None of these decisions. ANS:CPTS:1REF:SECTION 8. 1 6. The likelihood thickness work f(x) for a uniform irregular variable X characterized over the span [2, 10] is a. 0. 125 b. 8 c. 6 d. None of these decisions. ANS:APTS:1REF:SECTION 8. 1 7. In the event that the arbitrary variable X has a uniform dispersion somewhere in the range of 40 and 50, at that point P(35 ? X ? 45) is: a. 1. 0 b. 0. 5 c. 0. 1 d. unclear. ANS:BPTS:1REF:SECTION 8. 1 8. The likelihood thickness work f(x) of an irregular variable X that has a uniform dispersion among an and b is a. (b + a)/2 b. 1/b ? 1/a c. (a ? b)/2 d. None of these decisions. ANS:DPTS:1REF:SECTION 8. 1 9. Which of the accompanying doesn't speak to a persistent uniform irregular variable? . f(x) = 1/2 for x between ? 1 and 1, comprehensive. b. f(x) = 10 for x somewhere in the range of 0 and 1/10, comprehensive. c. f(x) = 1/3 for x = 4, 5, 6. d. None of these decisions speaks to a ceaseless uniform arbitrary variable. ANS:CPTS:1REF:SECTION 8. 1 10. Assume f(x) = 1/4 over the range a ? x ? b, and assu me P(X 4) = 1/2. What are the qualities for an and b? a. 0 and 4 b. 2 and 6 c. Can be any scope of x esteems whose length (b ? a) rises to 4. d. Can't reply with the data given. ANS:BPTS:1REF:SECTION 8. 1 11. What is the state of the likelihood thickness work for a uniform arbitrary variable on the stretch [a, b]? a. A square shape whose X esteems go from a to b. b. A straight line whose stature is 1/(b ? an) over the range [a, b]. c. A constant likelihood thickness work with a similar estimation of f(x) from a to b. d. These decisions are valid. ANS:DPTS:1REF:SECTION 8. 1 TRUE/FALSE 12. A constant likelihood dissemination speaks to an arbitrary variable having an unending number of results which may expect any number of qualities inside a stretch. ANS:TPTS:1REF:SECTION 8. 1 13. Consistent likelihood disseminations portray probabilities related with irregular factors that can accept any limited number of qualities along a span. ANS:FPTS:1REF:SECTION 8. 1 14. A constant arbitrary variable is one that can accept an uncountable number of qualities. ANS:TPTS:1REF:SECTION 8. 1 15. Since there is a limitless number of qualities a persistent irregular variable can accept, the likelihood of every individual worth is basically 0. ANS:TPTS:1REF:SECTION 8. 1 16. A ceaseless irregular variable X has a uniform conveyance somewhere in the range of 10 and 20 (comprehensive), at that point the likelihood that X falls somewhere in the range of 12 and 15 is 0. 30. ANS:TPTS:1REF:SECTION 8. 1 17. A ceaseless irregular variable X has a uniform appropriation somewhere in the range of 5 and 15 (comprehensive), at that point the likelihood that X falls somewhere in the range of 10 and 20 is 1. . ANS:FPTS:1REF:SECTION 8. 1 18. A persistent arbitrary variable X has a uniform appropriation somewhere in the range of 5 and 25 (comprehensive), at that point P(X = 15) = 0. 05. ANS:FPTS:1REF:SECTION 8. 1 19. We recognize discrete and nons top irregular factors by taking note of whether the quantity of potential qualities is countable or uncountable. ANS:TPTS:1REF:SECTION 8. 1 20. By and by, we every now and again utilize a ceaseless conveyance to estimated a discrete one when the quantity of qualities the variable can accept that is countable however exceptionally huge. ANS:TPTS:1REF:SECTION 8. 1 21. Let X speak to week by week pay communicated in dollars. Since there is no set furthest cutoff, we can't recognize (and in this manner can't tally) all the potential qualities. Subsequently, week after week salary is viewed as a ceaseless irregular variable. ANS:TPTS:1REF:SECTION 8. 1 22. To be a genuine likelihood thickness work, every single imaginable estimation of f(x) must be non-negative. ANS:TPTS:1REF:SECTION 8. 1 23. To be an authentic likelihood thickness work, every conceivable estimation of f(x) must lie somewhere in the range of 0 and 1 (comprehensive). ANS:FPTS:1REF:SECTION 8. 1 24. The total of all estimations of f(x) over the scope of [a, b] must rise to one. ANS:FPTS:1REF:SECTION 8. 1 25. A likelihood thickness work shows the likelihood for each estimation of X. ANS:FPTS:1REF:SECTION 8. 1 26. On the off chance that X is a constant arbitrary variable on the stretch [0, 10], at that point P(X 5) = P(X ? 5). ANS:TPTS:1REF:SECTION 8. 1 27. On the off chance that X is a consistent arbitrary variable on the span [0, 10], at that point P(X = 5) = f(5) = 1/10. ANS:FPTS:1REF:SECTION 8. 1 28. In the event that a point y lies outside the scope of the potential estimations of an irregular variable X, at that point f(y) must rise to zero. ANS:TPTS:1REF:SECTION 8. 1 COMPLETION 29. A(n) ____________________ irregular variable is one that accept an uncountable number of potential qualities. ANS:continuous PTS:1REF:SECTION 8. 1 30. For a consistent irregular variable, the likelihood for every individual estimation of X is ____________________. ANS: zero 0 PTS:1REF:SECTION 8. 1 31. Likelihood for persistent irregular factors is found by finding the ____________________ under a bend. ANS:area PTS:1REF:SECTION 8. 1 32. A(n) ____________________ irregular variable has a thickness work that appears as though a square shape and you can utilize zones of a square shape to discover probabilities for it. ANS:uniform PTS:1REF:SECTION 8. 1 33. Assume X is a constant arbitrary variable for X among an and b. At that point its likelihood ____________________ work must non-negative for all estimations of X among an and b. ANS:density PTS:1REF:SECTION 8. 1 34. The absolute territory under f(x) for a persistent irregular variable must rise to ____________________. ANS: 1 one PTS:1REF:SECTION 8. 1 35. The likelihood thickness capacity of a uniform irregular variable on the span [0, 5] must be ____________________ for 0 ? x ? 5. ANS: 1/5 0. 20 PTS:1REF:SECTION 8. 1 36. To discover the likelihood for a uniform arbitrary variable you take the ____________________ times the ____________________ of its relating square shape. ANS: base; tallness stature; base length; width; length PTS:1REF:SECTION 8. 1 37. You can utilize a consistent arbitrary variable to ____________________ a discrete irregular variable that takes on a countable, however exceptionally enormous, number of potential qualities. ANS:approximate PTS:1REF:SECTION 8. 1 SHORT ANSWER 38. A constant arbitrary variable X has the accompanying likelihood thickness work: f(x) = 1/4, 0 ? x ? 4 Find the accompanying probabilities: a. P(X ? 1) b. P(X ? 2) c. P(1 ? X ? 2) d. P(X = 3) ANS: a. 0. 25 b. 0. 50 c. 0. 25 d. 0 PTS:1REF:SECTION 8. 1 Waiting Time The time span patients must hold back to see a specialist at a crisis room in a huge emergency clinic has a uniform dissemination between 40 minutes and 3 hours. 39. {Waiting Time Narrative} What is the likelihood thickness work for this uniform dissemination? ANS: f(x) = 1/140, 40 ? x ? 180 (minutes) PTS:1REF:SECTION 8. 1 40. {Waiting Time Narrative} What is the likelihood that a patient would need to hold up somewhere in the range of one and two hours? ANS: 0. 43 PTS:1REF:SECTION 8. 1 41. {Waiting Time Narrative} What is the likelihood that a patient would need to stand by precisely 60 minutes? ANS: 0 PTS:1REF:SECTION 8. 1 42. {Waiting Time Narrative} What is the likelihood that a patient would need to stand by close to 60 minutes? ANS: 0. 143 PTS:1REF:SECTION 8. 1 43. The time required to finish a specific get together activity has a uniform circulation somewhere in the range of 25 and 50 minutes. a. What is the likelihood thickness work for this uniform circulation? b. What is the likelihood that the get together activity will require over 40 minutes to finish? c. Assume additional time was permitted to finish the activity, and the estimations of X were stretched out to the range from 25 to an hour. What might f(x) be for this situation? ANS: a. f(x) = 1/25, 25 ? x ? 50 b. 0. 40 c. f(x) = 1/35, 25 ? x ? 60 PTS:1REF:SECTION 8. 1 44. Assume f(x) approaches 1/50 on the stretch [0, 50]. a. What is the circulation of X? b. What does the chart of f(x) resemble? c. Discover P(X ? 25) d. Discover P(X ? 25) e. Discover P(X = 25) f. Discover P(0 X 3) g. Discover P(? 3 X 0) h. Discover P(0 X 50) ANS: a. X has a uniform conveyance on the span [0, 50]. b. f(x) structures a square shape of stature 1/50 from x = 0 to x = 50. c. 0. 50 d. 0. 50 e. 0 f. 0. 06 g. 0. 06 h. 1. 00 PTS:1REF:SECTION 8. 1 Chemistry Test The time it takes an understudy to complete a science test has a uniform conveyance somewhere in the range of 50 and 70 minutes. 45. {Chemistry Test Narrative} What is the likelihood thickness work for this uniform circulation? ANS: f(x) = 1/20, 50 ? x ? 70 PTS:1REF:SECTION 8. 1 46. {Chemistry Test Narrative} Find the likelihood that an understudy will take over an hour to complete the test. ANS: 0. 50 PTS:1REF:SECTION 8. 1 47. {Chemistry Test Narrative} Find the likelihood that an understudy will take no under 55 minutes to complete the test. ANS: 0. 75 PTS:1REF:SECTION 8. 1 48. {Chemistry Test Narrativ