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I need help with telecommunications homework problem?
It is necessary to transmit the human voice using a frequency range from 300 Hz to 3.5 kHz using a digital system.
(a) What is the minimum required sampling rate, according to theory?
(b) Why would a practical system need a higher rate than the one you calculated in part (a)?
2 AnswersEngineering8 years agoHelp with central limit theorem in statistics?
Among the adults in a large city, 30% have a college degree. A simple random sample of 100 adults is chosen. What is the probability that more than 35 of them have a college degree?
1 AnswerMathematics9 years agoHelp with Standard deviation in statistics?
A gas station earns $2.60 in revenue for each gallon of regular gas it sells, $2.75 for each gallon on midgrade gas, and $2.90 for each gallon of premium gas. Let X1, X2, and X3 denote the numbers of gallons of regular, midgrade, and premium gasoline sold in a day. Assume that X1, X2, and X3 have means μ1 = 1500, μ2 = 500, and μ3 = 300, and standard deviations σ1 = 180, σ2 =90, and σ3 = 40.
a.) Assuming X1, X2, and X3 to be independent, find the standard deviation of the daily revenue.
2 AnswersMathematics9 years agoHelp with statistics random variables?
After manufacture, computer disks are tested for errors. Let X be the number of errors detected on a randomly chosen disk. The following table presents values of the cumulative distribution function F(x) of X.
x F(x)
0 0.41
1 0.72
2 0.83
3 0.95
4 1.00
a) What is the probability that two or fewer errors are detected?
b) What is the probability that no errors are detected?
2 AnswersMathematics9 years agoHelp with voltage divider rule?
An electrical load has a power factor of 0.8 lagging. It dissipates 8 kW at a voltage of 200 V. Calculate the impedance of this load in rectangular coordinates.
1 AnswerEngineering9 years agoHelp with a statistics problem in conditional probability & independence?
Of all failures of a certain type of computer hard drive, it is determined that in 20% of them only the sector containing the file allocation table is damaged, in 70% of them only nonessential sectors are damaged, and in 10% of the cases both the allocation sector and one or more nonessential sectors are damaged. A failed drive is selected at random and examined.
1) If the drive is found to have a damaged allocation sector, what is the probability that some nonessential sectors are damaged as well?
2) If the drive is found to have a damaged allocation sector, what is the probability that NO nonessential sectors are damaged?
For the first problem I got 0.875 but not sure if that's correct and for the second problem I don't know how to figure it out because it is asking for no nonessential sectors damaged?
2 AnswersMathematics9 years agoI need help with a statistics problem in conditional probability & independence?
The article "Integrating Risk Assessment and Life Cycle Assessment: A Case Study of Insulation" estimates that 5.6% of a certain population has asthma, and that an asthmatic has probability 0.027 of suffering an asthma attack on a given day. A person is chosen at random from this population. What is the probability that this person has an asthma attack on that day?
2 AnswersMathematics9 years agoHelp with statistics counting method?
In a certain state, license plates consist of three letters followed by three numbers.
a. How many different license plates can be made?
I think I got this part correctly. For this I did 26*26*26*10*10*10 = 17,576,000 because it's 26 letters and 10 digits.
b. How many different license plates can be made in which no letter or number appears more than once?
c. A license plate is chosen at random. What is the probability that no letter or number appears more than once?
2 AnswersMathematics9 years agoNeed help with capacitance?
Find the capacitance of a parallel plate capacitor if the area of each plate is 0.1m^2 and the distance between the plates is 0.1 inch. The dielectric is air.
3 AnswersEngineering9 years agoFirst order linear differential equations help?
I just have a single question about this differential equation. Use first order of linear differential equation to solve this problem:
2(dy/dx) = 5 - 6y
I know the equation is (dy/dx) + P(x) y = Q(x) so my question is what do I do with the 2 that's in 2(dy/dx)? So far I did 2(dy/dx) + 6y = 5
3 AnswersMathematics10 years agoFirst order linear differential equations help?
How do I solve this differential equation using the first order linear differential equations?
dy + 3ydx = e^(-3x) dx
3 AnswersMathematics10 years agoDifferential equations help?
How do I solve this differential equation using separation of variables?
Am I suppose to plug in the zeros for t and s?
ds/dt = sec(s); t = 0 when s = 0
3 AnswersMathematics10 years agoI need help with differential equations?
How to solve this differential equation using separation of variables?
2dy/dx = y(x+1) / x
3 AnswersMathematics10 years agoHelp with differential equations?
I need help solving this differential equation using separation of variables:
ydx + xdy = 3xydx
3 AnswersMathematics10 years agoClock Signals and Clocked Flip-Flops help?
A certain clocked FF has minimum ts = 20 ns and th = 5 ns. How long must the control inputs be stable prior to the active clock transition?
3 AnswersEngineering10 years agoHelp finding the radius of convergence?
Find the radius of convergence (R), and the convergence interval, for the following power series:
∞
Σ (2^n / n!)(x - 1)^n ; (a = 1)
n=0
So far I've gotten lim(n→∞) (2^(n+1)*((x-1)^(n+1)) / (n+1)!) * (n! / ((2^n)(x-1)^n)). I have no idea what to do after that.
2 AnswersMathematics10 years agoHelp finding the radius of convergence?
Find the radius of convergence (R), and the convergence interval, for the following power series:
∞
Σ (1/n)x^n
n=0
I tried using the ratio test but can't figure out the radius of convergence
1 AnswerMathematics10 years agoHow to find the inverse of a diagonal matrix?
Find A^-1 if A =
[alpha, 0, 0]
[0, beta, 0]
[0, 0 , epsilon]
I've looked online and notes that the answer is:
[1/alpha, 0, 0]
[0, 1/beta, 0]
[0, 0, 1/epsilon]
I want to know why. Examples on youtube and my notes do not explain the steps. All they say is that the inverse is 1 over the element.
4 AnswersMathematics10 years agoNeed help on a physics current problem?
If a conductor with a current of 200 mA passing through it converts 40 J of electrical energy into heat in 30 s, what is the potential drop across the conductor?
1 AnswerPhysics10 years agoCan't download any apps in the Android market?
I just got my Samsung Captivate Galaxy S phone yesterday and I created a Google account so I can download some applications but I can't seem to download anything. Whenever I want to download an application it would only say "starting downloading" for hours and not actually download. Also to add that I'm using Wi-Fi not 3G because I do not want to use my data. Is AT&T's severs down or is it my phone or google account?
4 AnswersMobile Phones & Plans10 years ago