#$&* course MTH 152 Time: 4:09 PMDate: 7/19 If your solution to stated problem does not match the given solution, you should self-critique per instructions at
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Given Solution: `aThe choice of the second is influenced by the first choice. If a Republican is chosen on the first choice, then there are fewer Republicans available for the second choice and the probability of getting a Republican on the second choice is lower than if a Republican had not been chosen first. COMMON ERROR: they are independant because they were randomly selected....if it is random then one did not depend on the other. EXPLANATION: The selection was indeed random, but the makeup of the remaining group available on the second choice depends on the first choice. ** Self-critique: - Okay. Am I correct in assuming that in my example relates to the question?
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Given Solution: `a There are 13 primarily motivated by money and 14 by creativity. Each person can have only one primary motivation so there is no overlap between these two groups. There are thus 13 + 14 = 27 motivated by money or creativity, out of a total of 66 women, which gives probability 27 / 66 = 9/22 = .41 approx.. If M is the set motivated by money, C the set motivated by creativity and S the entire sample space then we have p ( M or C) = p(M) + p(C) - p(M and C) or in set notation p(M U C) = p(M) + p(C ) - p(M ^ C), with U and ^ standing for set union and intersection. Since M ^ C is empty, p(M ^ C) = 0. p(M) = n(M) / n(S) = 13 / 66 and p(C) = n(C) / n(S) = 14/66 so we have p (M U C) = 13/66 + 14/66 = 27/66 = 9/22 = .41 approx. ** Self-critique: - I should note that my answer reflects on the total, in my edition, being 42 females. - Which ultimately yielded my solution above. ------------------------------------------------ Self-critique Rating: Good to go. See my comment above relating to the book information being different from yours. ********************************************* question: Query 12.3.24 prob of club 2d given diamond first What is the desired probability and how did you obtain it? YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY Your solution: - There are 13 diamonds out of 52 cards. When one is drawn, without replacement, this leaves 51 cards remaining in the deck. - Choosing a diamond has no effect on the number of clubs, however. - This is shown as 13/51 = 25.4% confidence rating #$&*: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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Given Solution: `aThe probability is 13 / 51. When the second card is chosen there are 13 clubs still left, out of 51 remaining cards. This can also be calculated using P(A|B) = P(A^B) / P(B). The probability of getting a diamond on the first card and a club on the second is 13/52 * 13/51. The probability of getting a diamond on the first card is 13/52. So the probability of a club on the second given a diamond on the first is (13 / 52 * 13 / 51) / (13/52) = 13/51. ** Self-critique: - I right my conditional probability formula as “P (B | A) = P (A ^ B) / P (A) “ Would this effect the outcome? - What’s more, how does simple division determine the chances of selecting two cards in a row?
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Given Solution: `aOf the 26 red cards, 13 are diamonds. So the probability of a diamond, given red, is 13/26 = 1/2. ** Self-critique ------------------------------------------------ Self-critique Rating: I now see why it’s a point to say it’s red; it decreases the number of the collection of cards to 26 rather than 52. ********************************************* question: Query 12.3.38 & 36 P(sale > $100) = .8; prob that first three sales all >$100 What is the probability that the first three sales are all for > $100 and how did you obtain your result? YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY Your solution: - Since the sales are independent of each other, use the FCP to multiply .8 * .8 * .8 = .512 = 51.2% chance the first three sales will be over $ 100 confidence rating #$&*: 2 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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Given Solution: `athe first sale has to be > $100, AND the second sale has to be > $100, AND the third sale has to be > $100. The events are independent. So the total probability, by the fundamental counting principle, is .8 * .8 * .8 = .512. ** Self-critique: - What if the events are Dependent of each other?
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Given Solution: `aOn a given day cloud movement is not in critical direction with probability 1 - .05 = .95. this has to occur on the first day, then it has to occur on the second day, then on the third, then on the fourth, then on the fifth. These events are considered independent so the probability is .95 * .95 * .95 * .95 * .95 = .774 approx. (use your calculator to get the accurate answer). In order for none of the five days to have cloud movement in the critical direction, each of the five days must not have movement in the critical direction. The probability that the movement will not the in the critical direction for each of the days is .95. The probability that this will happen on every one of the five days is therefore .95 * .95 * .95 * .95 * .95 = .774, approx. ** Self-critique: - Why is any given day going to be 1 - .05? Would the same be true for any three given days being 3 - .05 and so on? Under the assumption that the probability is n - d (where ‘n’ denotes number of days in question and ‘d’ denotes the percentage of the HCl emission cloud moving in the critical direction)? ------------------------------------------------ Self-critique Rating:
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Given Solution: `aThere is a .52 probability of getting heads, then there is a .48 probability a getting tails. The two events have to happen consecutively. By the Fundamental Counting Principle there is thus a probability of .52 * .48 = .2496 of getting Heads then Tails. ** &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Self-critique (if necessary): - What is the relationship between consecutive events and multiplication? Does this translate to a relationship between random events and division? ------------------------------------------------ Self-critique Rating:
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Given Solution: `aThe probability of rain on the first of the four days is .3, since it is given that there was no rain on the previous day. The probability of rain on each of the following for days is .8, since on each of these days it rained the day before. The probability of rain on all four days is therefore .3 * .8 * .8 * .8 = .154. ANOTHER WAY OF SAYING IT: Oct 31 was clear so the probability of rain on the first day is .3. If it rained on the first day of the month then there is a probability of .8 that it rains on the second day. If it rained on the second day of the month then there is a probability of .8 that it rains on the third day. If it rained on the third day of the month then there is a probability of .8 that it rains on the fourth day. So the probability of rain on all 4 days is .3 * .8 * .8 * .8 = .154 ** Self-critique: - I wondered why you assumed it would rain on a day that yielded a 30% chance, but I glanced at the question, which gave a constraint that it must rain on three consecutive days. Is this the reason why one would assume it rains on 30% chance? ------------------------------------------------ Self-critique Rating:
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Given Solution: `aTo get rain on 3 consecutive days requires rain on the first day, which happens with probability .5; then rain on the second day given that there was rain on the first day, which is .8, then rain on the third day, given that there was rain on the previous day; this third probability is also .8. The probability of the 3 events all happening (rain of 1st day AND rain on the second day AND rain on the third day) is therefore .5 * .8 * .8 = .32. ** QUESTION ON PROBLEM 33: Please explain Problem 33 of 12.3. It reads: If one number is chosen randomly from the intergers 1 throught 10, the probability of getting a number that is odd and prime, by the general multiplication rule is P(odd) * P(prime/odd) = 5/10 * 3/5 = 3/10 My question is how did we get three prime numbers out of 1 through 10? I assumed there were 4 of them (2, 3, 5, and 7). ** ONE ANSWER: The sample space is reduced to odd numbers, and 2 is not odd. So the set within the restricted sample space {1, 3, 5, 7, 9} should just be {3, 5, 7}. ANOTHER ANSWER: If we don't use the restricted sample space then we have P(prime | odd ) = P(prme) * P(odd | prime). We find P(prime) and P(odd | prime). P(prime) = 4 / 10, since there are 4 primes between 1 and 10. Within the unrestricted sample space P(odd | prime) is 3 / 4 since of the primes 2, 3, 5, 7 only three are odd. }Thus when you multiply P(prme) * P(odd | prime) you get 4/10 * 3/4 = 3/10, just as before. ** Self-critique ------------------------------------------------ Self-critique Rating: ********************************************* question: Query Add comments on any surprises or insights you experienced as a result of this assignment. - Refer to my inquiry about the relationship of probability and multiplication, I may be on to something. For your convenience, I’ve posted it again below: What is the relationship between consecutive events and multiplication? Does this translate to