Suppose that a random sample of size 64 is to be selected from a population with mean 40 and standard deviation 5.

a) What is the approximate probability that x will differ from μ by more than 0.8? (Round your answer to four decimal places.)

The standard deviation of quarterly changes in the price of a commodity is $0.65, the standard deviation of quarterly changes in a futures price on the commodity is $0.81, and the coefficient of correlation between the two changes is 0.8. What is the minimum variance hedge ratio for a 3-month contract

Test the hypothesis that the average number of T.Vs in U.S. households is less than 3. Your sample consists of 100 households with a mean of 2.84 T.Vs. You know the population standard deviation to be 0.8. Your desire a level of significance of 0.05

Q1A 4-poles, wave wound, 600 conductors DC long shunt generator has the armature, series and shunt resistances are 0.15 ohm, 0.18 ohm and 200 ohm respectively. It runs at 1500 rpm. Calculate the following if it is required supply to the load resistance of 20ohm with flux per pole as 8.33 mWb. Take the Iron and Frictional losses as 550 W.(i)Induced Emf(ii)Terminal Voltage(iii)Output Power(iv)Input Power(v)Efficiency

Q2Write short notes on following characteristics of dc generator(i) Open Circuit Characteristics (OCC)(ii) Load Characteristics

Q3A dc short shunt generator supply 500V to a 20 kW load. Its armature, series and shunt resistance are 0.8 , 0.6 and 700 respectively. Calculate the armature current, induced emf, input power, torque supplied by the prime mover and efficiency if its speed and mechanical losses are 1500 rpm and 910W respectively.

Q4A 500V, 4 poles, wave-wound DC Series Motor has 900 conductors on its armature. It has armature and series field resistance of 0.6, and 0.8respectively. The motor takes a current of 40A. Estimate the speed and gross Torque developed if it has a flux per pole of 20mWb.

Q5A dc shunt motor takes a no load current of 5 A at 300V. Its armature and shunt resistances are 0.45 ohm and 0.68 ohm respectively. Calculate the Constant Loss (Iron and Frictional Loss) of the machine.

Q6A dc series motor operates at 1000 rpm with a line current of 82A from 250V mains. its armature circuit resistance is 0.2and its field resistance is 0.6. Find the speed at which the motor runs at a line current of 65A, assuming that the flux at this current is 33% of the flux at 82A.

Q7A 3 phase, 50Hz, 4 poles induction motor runs at 1440 rpm. Calculate the following i.Synchronous speedii.Slipiii.Slip speediv.Rotor frequency while runningv.Rotor cu loss if mechanical power developed is 16 kW.

Q8A 40 kW (Rated Output), 415V, 50Hz, 3 phase, star connected induction motor has a synchronous speed of 1800 rpm. The full load slip is 4% and full load power factor is 0.9 lagging. Stator Cu losses are 2500 W. Iron losses are 2000W. Rotational losses are 1400 W. Calculate i.Shaft or Net Torque developedii.Mechanical power developediii.Power inputiv.Efficiencyv.Supply current

Q9The following are the equivalent circuit parameters of a 3phase, star connected 415V, 50Hz, 4 poles Induction Motor:R1= 0.5, R'2= 0.4/s , X1= 0.9, X'2= 0.8, Xm= 50,(neglect Ro)Calculate the input impedance, motor current, power input, power supplied to the rotor, power developed and efficiency if its rotational losses are 1200W. It runs at 1410 rpm.

Q10A 415-V, 29.84 kW, 50 Hz, delta-connected 3-phase induction motor gave the following test data:No load test:415V, 15A, 2000 WLocked rotor test:125V, 40A, 4000 WConstruct the circle diagram and determine the line current and power factor for the rated output. Assume stator and rotor Cu losses equal at standstill.Q11With a aid of neat circuit diagram, explain the working principle of Automatic star-delta starter of three phase induction motor

We wish to create a 95% confidence interval for the proportion. A sample of 50 gives a proportion of 0.2. Find the upper value for the confidence interval. Round to 3 decimal places.

Two assets' correlation is -0.2. The first has expected return of 9% and standard deviation of 16%, the second has expected return of 13% and standard deviation of 20%.

Calculate the minimum amount of risk (standard deviation) you'll need to take if investing in these two assets. (Provide your answer in percent rounded to two decimals omitting the % sign)

1) A force of 2 pounds is required to hold a spring stretched 0.2 feet beyond its natural length. How much work (in foot-pounds) is done in stretching the spring from its natural length to 0.9 feet beyond its natural length?

2) Work of 3 Joules is done in stretching a spring from its natural length to 19 cm beyond its natural length. What is the force (in Newtons) that holds the spring stretched at the same distance (19 cm)?

3) How much work is done lifting a 40-pound object from the ground to the top of a 30-foot building if the cable used weighs 0.5 pounds per foot?
foot-pounds.

Time intervals measured with a stopwatch typically have an uncertainty of about 0.2 seconds due to human reaction time. How does this compare to the uncertainties of individual measurements above? Can human reaction time fully account for these uncertainties? If not, what other factors may contribute to the uncertainty of individual measurements (provide at least one)?

Also, What are the fundamental differences in the uncertainty of individual measurements vs uncertainty of mean of measurements

Suppose that the price elasticity for hip replacement surgeries is 0.2. Further suppose that hip replacement surgeries are originally not covered by health insurance and that at a price of $50,000 each, 10,000 such surgeries are demanded each year.

Instructions: Enter your answers as whole numbers.

a. Suppose that health insurance begins to cover hip replacement surgeries and that everyone interested in getting a hip replacement has health insurance. If insurance covers 70 percent of the cost of the surgery, by what percentage would you expect the quantity demanded of hip replacements to increase? (Hint: Do not bother to calculate the percentage changes using the midpoint formula. If insurance covers 70 percent of the bill, just assume that the price paid by consumers falls 70 percent.)

What if insurance covered 95 percent of the price?

Instructions: Round your answer to 1 decimal place.

b. Suppose that with insurance companies covering 95 percent of the price, the increase in demand leads to a jump in the price per hip surgery from $50,000 to $100,000. How much will each insured patient now pay for a hip replacement surgery?

Compared to the original situation, where hip replacements cost $50,000 each but people had no insurance to help subsidize the cost, will the quantity demanded increase or decrease?

(Click to select)  Increase  Decrease

By how much?