1.7 Read all of the classic papers cited in Section 1.7. Compose a 500–1000 word paper (or 8–12 slide PowerPoint presentation) that summarizes the key concepts that emerge from these papers, emphasizi
1. A researcher suspected that the number of between meals snacks eaten by students in a day during final examinations might depend on the number of tests a students had to take on that day. The accompanying table shows joint probabilities, estimated from a survey
Number of tests (X)
Number of snacks(Y)
0
1
2
3
0
0.07
0.09
0.06
0.01
1
0.07
0.06
0.07
0.01
2
0.06
0.07
0.14
0.03
3
0.02
0.04
0.16
0.04
a. Find the probability distribution of X and compute the mean number of test taken by students on that day
b. Find the probability distribution of Y and compute the mean number of snacks by students on that day
c. Find and interpret the conditional probability distribution of Y given that X=3.
d. Find the covariance between X and Y
e. Are number of snacks and number of tests independent?
1.A market can be described by the equations Qd = 100 A????1 P and Qs= P. What are the equilibrium price and quantity in thismarket?
A. The equilibrium price is $50 and the equilibrium quantity is50 units.
B. The equilibrium price is $100 and the equilibrium quantity is100 units.
C. The equilibrium price is $0 and the equilibrium quantity is 0units.
D. The equilibrium price is $0 and the equilibrium quantity is100 units.
2. In free markets, shortages lead to:
A. lower prices.
B. higher prices.
C. surpluses.
D. unexploited gains from trade
3 The demand curve for Froot Loops breakfast cereal is veryelastic because:
A. most breakfast cereals are considered a luxury good.
B. there are many good substitutes for Froot Loops.
C. the demand curve is negatively sloped.
D. it is one of the most advertised cereals in the world.
4.Which good below might be expected to have the most inelasticdemand curve?
A. salt
B. women’s blouses from Walmart
C. potato chips
D. Tylenol
1. A patient lives for two periods, 1 and 2. Her well-being in period 2 depends on her state of health, s = 0, in which larger numbers imply better health status, as well as some healthrelated action t = 0 which is taken in period 1, but has a health impact in period 2. The patient derives utility from two sources. First, she gets instantaneous instrumental utility in period 2 from having her health behaviour match her health state. Formally, her instrumental utility is (-|s-t|). This means that in terms of instrumental utility, it is always optimal to align the action with the state, that is to set t = s. As an example, lower values of t could represent taking health concerns more seriously, for instance by doing x-rays. Then, instrumental utility implies that a more concerning health condition calls for more serious intervention. Notice that in this specific model, the variable t does not affect the health state s (the two are independent) but the well-being. Secondly, the patients derives anticipatory utility in period 1 from her beliefs about her health condition in period 2. The patient’s initial belief is that with probability p = 0.3 her health state will be s1 = 36 and with probability 1 – p = 0.7, it will be s2 = 49. Her anticipatory utility, which depends on her expected health state given her beliefs is 22· v p · s1 + (1 – p)s2. The patient’s expected total utility in period 1, which combines expected instrumental utility in period 2, plus anticipatory utility in period 1, is thus: 22 · v p · s1 + (1 – p)s2 – p|s1 – t| – (1 – p)|s2 – t| In period 1, the patient has the option of visiting a doctor to get diagnosed. The visit is free, and will remove any doubt about her future value of s. (In other words, her beliefs 1 about p will go either to p = 0 or to p = 1). If she does not visit the doctor, she will not learn any information about s, and will keep believing that the two states are equally likely. After deciding whether to go to the doctor, and after getting the diagnosis if she does go, the patient then chooses what health action t to take. (a) Write the patient’s expected total utility in period 1 as a function of t, if she decides NOT to visit the doctor. What level of intervention t (e.g. a diet) she selects? What is her expected total utility given the optimal t? (Hint: the EU function has components with absolute value. It is advisable to draw pen and paper the EU first in order to understand the problem… ) (b) Write the patient’s expected total utility as a function of t if she visits the doctor and gets a bad diagnosis, that is p = 1, so that her future health status is s1 = 36 for sure. What level of intervention t does she choose? What is her utility given the optimal t? (c) Repeat the exercise in part (b) for the case in which the patient visits the doctor and gets a good diagnosis, i.e. p = 0, so that her future health condition is s2 = 49 for sure. (d) Write the patient’s expected total utility from deciding to visit the doctor, not knowing which diagnosis she will get. This is the weighted sum of the utilities in (b) and (c), with the weights equal to the probabilities of the two possible diagnoses. Will the patient decide to visit the doctor? (e) Now suppose that the patient’s possible negative diagnosis is extreme sickness, that is s1 = 10. The other possibility is still s2 = 49, with the two health states still being determined by p and 1 – p. Using the same steps as in parts (a) through (d), solve for whether the patient goes to the doctor. (f) Conventional wisdom says that when information is more important for making choices, a person is more likely to seek out that information. Thus, availability of information about health risks and the effect of health behaviours is an optimal policy. How does the consideration of anticipatory utility alter this conventional paradigm? Is that true in the above case? 2. Consider the model we used to explain the representativeness heuristics in class (i.e. the Freddy model) and imagine Freddy’s psychology is such that the ”urn” size is N = 10. Suppose Freddy observes quarters of performance by fund manager Helga. Helga may be a skilled, mediocre or unskilled manager. A skilled fund manager has a 3/4 chance of beating the market each quarter, a mediocre manager has a 1/2 chance of beating the market each quarter and an unskilled manager has a 1/5 chance of beating the market each quarter. Because Freddy is an avid Bloomberg subscriber, he knows these odds. Importantly, in reality the performance of managers are independent from quarter to quarter. (a) Suppose first that Freddy thinks Helga is mediocre. What does Freddy think is the probability that Helga beats the market in the first quarter? Suppose that she actually beats the market on the first quarter. What does Freddy think is the probability she does it again? Suppose that she beats the market again. What does Freddy think is the probability that she will do so a third time? (b) How do the three probabilities in part (a) relate to each other? What sort of psychological bias does this reflect? (c) Now suppose that Freddy does not know whether Helga is skilled, mediocre or unskilled. He has just observed two consecutive quarters of under performance by Helga. Can he conclude which type of manager Helga is? Can he rule out any of the three type? If not, how many additional rounds he needs to conclude something? Explain your intuition… 2 (d) How many more quarters of under performance does Freddy need to observe in order to be sure of Helga’s type? (e) Now, let assume that Freddy observes the performance of a large sample of hedge-fund managers over two quarters. The sense of the next part of the exercise is to derive what Freddy concludes about the proportion of skilled, mediocre, and unskilled managers in the population. In reality, all managers in the market are mediocre. i. Let’s compute the proportions that Freddy (and any other trader) observes. What proportion of managers will beat the market twice? What proportion will have two under-performances? What proportion will have mixed performances? . ii. Suppose Freddy though that the proportion of skilled, mediocre, and unskilled managers in the population was q˜, 1-2˜q, and q˜, respectively. What does Freddy expect should be the proportion of managers who show two above-market performances in a row? iii. Given your answers to the previous two parts, what does Freddy infer is the proportion q˜ of skilled managers in the population? Provide an intuition for your answer 3. Explain, in your own words, what is the fallacy exemplified in the below excerpt. ”Correlations between the USD price of cryptoassets are constantly fluctuating due to a variety of factors – one of the most important factors is market irrationality <…> which has an effect similar to co-movement phenomenon. The below chart displays the average correlation, in USD prices, amongst all crypto currencies. The data shows that whenever correlations between these coins reach a specific positive upper bound between 0.8 and 1.0, the trend of Bitcoin against USD tends to reverse, or at least halts the previous price action. The cumulative duration of these periods totaled 513 days, or more than one-quarter of the entire sample range, indicating that the crypto market is prone to show extreme correlations. On average, these “0.8+ correlation periods” lasted for durations of about 39 days, with an average maximum correlation of 0.901. The most recent “peak correlation period” lasted 90 days until March 14, the longest such period in crypto-history. That coincided with Bitcoin’s fall from the 6, 000 range to the 3, 000 range. This high correlation suggests that market sentiment has already found a local maximum during that period, and a trend reversal may possibly ensue. Such a price movement pattern, to some extent, may reflect both the irrational behavior of market participants and some inherent traits of a young market.”. (Binance Research – Investigating Cryptoassets Cycles )
Attachments:
BE-PS3.pdf
1.A group of researchers conducted an experiment to determine which vaccine is more effective for preventing getting the flu. They tested two different types of vaccines: a shot and a nasal spray. To test the effectiveness, 1000 participants were randomly selected with 500 people getting the shot and 500 the nasal spray. Of the 500 people were treated with the shot, 80 developed the flu and 420 did not. Of the people who were treated with the nasal spray, 120 people developed the flu and 380 did not. The level of significance was set at .05. The proportion of people who were treated with the shot who developed the flu = .16, and the proportion of the people who were treated with the nasal spray was .24. The calculated p value = .0008.
We have to research Is there any significant difference between two typres of vaccine i.e, a shot and nasal spray used for preventing nasal spray?
1. A gearbox is modeled as which comprises two identical gears of moments of inertia J1 and N1 teeth, meshing with two identical pinions of moments of inertia J2 and N2 teeth. All three shafts have stiffness k. For the relations given below:
find the natural frequencies and natural modes of the system. Sketch the latter.
2. Derive a procedure to obtain the zero-state response of a two-dof semidefinite system that does not preserve the generalized—translational or angular— momentum. To this end, use as an example the belt-pulley system.
1.According to service quality model, willingness of employees to solve problems of customers is classified as A. responsiveness B.assurance C.empathy D.reliability 2. Considering categories of services mix, air travel with eatable is classified as A. tangible goods with accompanying services B.pure tangible goods C.pure services D.major service with minor goods 3. Legal staff, computer operators and accountants are examples of services of A. government sector B.private non-profit sector C.manufacturing sector D.business sector 4. Hospitals, loan agencies, postal services and schools are examples of services of A.government sector B.private non-profit sector C.manufacturing sector D.business sector 5. Act of specific performance offered by one party to another and tangible in nature is classified as A.service B.product C.co-branding D.None of the above
1.A group of researchers conducted an experiment to determine which vaccine is more effective for preventing getting the flu. They tested two different types of vaccines: a shot and a nasal spray. To test the effectiveness, 1000 participants were randomly selected with 500 people getting the shot and 500 the nasal spray. Of the 500 people were treated with the shot, 80 developed the flu and 420 did not. Of the people who were treated with the nasal spray, 120 people developed the flu and 380 did not. The level of significance was set at .05. The proportion of people who were treated with the shot who developed the flu = .16, and the proportion of the people who were treated with the nasal spray was .24. The calculated p value = .0008.
We have to research Is there any significant difference between two typres of vaccine i.e, a shot and nasal spray used for preventing nasal spray?
1. According to the EF, is the human population living at, beyond or below the Earth’s natural biocapacity? For how long has this been the case? Is this sustainable? (4 marks) 2. According to the EF, is the Chinese population living at, beyond or below China’s natural biocapacity? For how long has this been the case? Is this sustainable? (4 marks) 3. If you assume that EF grows at a constant yearly rate, what is the approximate slope of the EF relationship with time for China? And what is its units? Give the equation of, and sketch this line, with EF on the vertical axis and year on the horizontal axis. (EF for 2012 is 3.4 and for 1961 was approximately 1). (4 marks) 4. If you assume that biocapacity grows at a constant yearly rate, what is the approximate slope of the biocapacity relationship with time for China? And what is its units? Give the equation of, and sketch this line, with biocapacity on the vertical axis and year on the horizontal axis. (biocapacity for 2012 is 0.9 and for 1961 was approximately 1). (4 marks) 5. If this trend continues, what will EF and biocapacity be in 2050? (Hint: use your equation from questions 3 and 4.) What will biocapacity minus EF be in 2050? Will there be a deficit or reserve? (4 marks) 6. Use the data presented in Figure 1 to suggest a policy to make land use sustainable. (4 marks)
The model describes the evolution of a population over time ??. ??(??) = ??0?? (??-??)?? (1) where ??0 is the population at time ?? = 0. 1. If the initial population is ??0 = 2000, the annual birth rate ?? = 0.03 (3% exponential birth rate) and annual death rate ?? = 0.02 (2% exponential death rate), what is the population after 1 year? Explain this result. (4 marks) 2. Find an expression for the growth rate (population change) of the population in terms of time and the parameters. Hint: differentiating with respect to time gives a rate of change. (4 marks) 3. If ??
The model in equation (1) in Part A describes a population untouched by humans: there is no harvesting. We can model what happens if we harvest ?? individuals from the population each period. The unlimited population growth with harvesting model is given by ??(??) = ???? (??-??)?? + ??-???? (??-??)?? (??-??) (2) where ?? is the birth rate, ?? is the death rate, and ?? is the number of individuals taken from the population in each period. 1. Confirm that the rate of population change is ????(??) ???? = (?? – ??)??(??) – ??. (3) (5 marks) 2. Give the meaning of the expression in equation (3). (4 marks) 3. Let ??0 = ??(0) = 2000, ?? = 0.05 and ?? = 0.02. At what rate can the population be harvested sustainably? Hint: The sustainable harvest, ??, will be the value that causes no change in the overall population, i.e. ????(??) ???? = 0. (4 marks) 4. Suppose an ecosystem is being sustainably harvested at exactly its replacement rate, and the population is constant. Now suppose the population experiences a brief disease epidemic, which causes 4% of individuals to perish. What will happen to the population if harvesting continues at the same rate? (4 marks) 5. Suppose a population of fish that follows this model is being harvested sustainably, as before. What will happen in the long run if, one day, a fisherman decides to throw one of the fish back? (4 marks) 6. This type of model is often said to have a “knife-edge” equilibrium. Explain what this means. (4 marks) 7. Governments often levy fishing quotas in areas where populations are at risk. Does this model shed any light on the effectiveness (or otherwise) of these policies? (Hint: what if someone cheats?) (4 marks)
A model linking these ideas was first proposed by a French mathematician Pierre Verhulst in 1838. The Verhulst model can be written as: ??(??) = ??0?? ???? 1+ ??0(?? ????-1) ?? (4) where ??0 is the initial population level. For simplicity, we’ll write the net reproduction rate simply as ??, rather than in terms of births and deaths. 1. What is the growth rate if the initial population is zero? (4 marks) 2. When the population is initially at its carrying capacity, i.e. ??0 = ??, what is the population at time ??? How does the population level change when the growth rate r increases? (4 marks) 3. Differentiate (4) to show that the rate of population growth at time t is ????(??) ???? = ????(??) (1 – ??(??) ?? ) (5) Remember to use the quotient rule to differentiate (4). You will find it easier if you carefully look for the terms that you expect to see in the final expression, and factor those out. (5 marks) 4. Does the population grow faster when it is above the environment’s carrying capacity (N>K), or below it (??
Attachments:
V2.pdf
1. (a) For the circuit shown in FIGURE 1 sketch the voltage waveform across the secondary winding of the transformer. On the same diagram sketch the load voltage waveform. The sketches should take into account diode voltage drops. Indicate the following on the sketches: (i) when diodes are conducting and in what order (ii) when the capacitor is charging and discharging (b) With the aid of the above voltage waveform sketches, briefly explain the operation of the circuit. Document Preview:
(a) For the circuit shown in FIGURE 1 sketch the voltage waveform across the secondary winding of the transformer. On the same diagram sketch the load voltage waveform. The sketches should take into account diode voltage drops. Indicate the following on the sketches: when diodes are conducting and in what order when the capacitor is charging and discharging With the aid of the above voltage waveform sketches, briefly explain the operation of the circuit. T1 vSECONDARYDD1ESUPPLY2 D3D4 C1vCRL 10 : 1 FIG. 1 Teesside University Open Learning© Teesside University 2011 Created with an evaluation copy of Aspose.Words. To discover the full versions of our APIs please visit: https://products.aspose.com/words/ The source voltage for the power supply circuit shown in FIGURE 1 is mains, i.e. 230 V rms at a frequency of 50 Hz. Calculate the following for a load resistance of 25 ? and a smoothing capacitance of 1000 µF: rms and peak voltage across the secondary winding of the transformer the peak voltage across the capacitor the peak-to-peak and rms ripple voltages the load d.c. voltage and current. Model the power supply circuit using PSPICE and use the simulation to plot the load and ripple voltages, the current in the capacitor and a diode. Compare the waveforms with the values calculated above and attempt to account for any discrepancies. Briefly explain the function and operation of TR1, TR2, R1 and R1 in the circuit shown in FIGURE 2. R2 TR1 Created with an evaluation copy of Aspose.Words. To discover the full versions of our APIs please visit: https://products.aspose.com/words/ R1 TR2 Voltage regulator InOut Common Created with an evaluation copy of Aspose.Words. To discover the full versions of our APIs please visit: https://products.aspose.com/words/ VINRLOAD FIG. 2 Teesside University Open Learning© Teesside University 2011 Created with an evaluation copy…
Attachments:
em201852abd95….doc
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