# variables

1. ### Normalization of Two Mean Random Variables

Hello, I am dealing with the following question: My question is, once we Find X_1 - X_2 do I treat their normal distribution as, say X_3 and do the usual standardization procedure? I have attached my attempt at the problem, could someone please verify if I'm on the right track. Thank you...
2. ### simple linear regression with zero variables

Simulate a simple random sample y1,y2,…,y8 of size 8 from an NID(50,102) distribution. Compute the least squares fit to the model y∼β1+ε. Repeat at least 500 times. Compare the simulated values of β̂ 1 to the underlying NID(50,102) distribution in terms of (1) location, (2) spread, and (3) shape.
3. ### second order differential equation with two variables, please have a look

Dear Sir, Madam, I hope you are doing well.. At first let me introduce myself.. I am Mudhar an international Ph.D student in the University of Bradford, United Kingdom working in modeling of reverse osmosis units for wastewater treatment. Actually I have stacked with a solution of second order...
4. ### Stepwise Logit Regression - Drop of variables

Dear All, I have a small question I hope you could help me with. I am trying to find a predictive model for a dataset doing a stepwise logit regression. I have a few variables with info that is included in another variable. E.g. "income" (0-9 with 0=income is missing) and "income missing"...
5. ### Please looking for a solution of a secondary differential equation with two variables

Dear Sir, Madam, I hope you are doing well.. At first let me introduce myself.. I am Mudhar an unternational Ph.D student in the University of Bradford, United Kingdom working in modeling of reverse osmosis units for wastewater treatment. Actually I have stacked with a solution of second order...
6. ### Seperate the Variables or Exact Equation Method?

(y^{2} - 2x) dx + (2xy + 1)dy = 0 Is exact method the only way to solve, or can we use seperation of variables?
7. ### Polynomial system of 6 variables

U = A a² V = 2 A a b W = A b² u = 2 A a c + B a v = 2 A b c + B b w = A c² + B c + C I'd like to solve this system for A, B, C, a, b, c. Is it possible!?
8. ### Arithmetic Sequence with two variables

This is the question: Given the sequence a+b, 2a-b, 3a-3b,_,_,_,_,8a-13b, insert four arithmetic sequence. I can do it if it only has one variable, but our teacher hasn't taught us this. Please help Thanks in advance
9. ### Many variables with fewer equations

This question involves basic algebraic operations. Is there any trick to solve it? (Here is the link to the question image- https://drive.google.com/file/d/0B4uz7PRqr_oiYlJyZzJ3MV9DMlU/view?usp=sharing)
10. ### Distributions of funcation of random variables

Draw 15 cards at random and without replacement form a pack of 25 card numbered 1,2,3,...,25. Find the probability that 10 is the median of the card selected. Need help
11. ### Which statistical variables used to differentiate?

Which two tests or variables can you determine these two graphs?
12. ### Change of Variables - Vector Calc

Use an appropriate change of variables to evaluate where D is the triangle with vertices (0,0), (0,4), and (2,2). So I tried to use a transformation, and got T(u,v) = (2u, 2u+4v). This made my Jacobian = 8, and my new integral . However, this doesn't seem to be any easier to integrate. I'm not...
13. ### Calculus of variations changing variables

Hi Im am given the functional S[y]=\int_{a}^{b}\frac{x^{3}y^{\prime2}}{y^{4}} dx I am asked to show that if x=u^\beta and with an appropriate value for \beta that S[y]=\int_{B}^{A}\frac{y^{\prime}(u)^{2}}{y^{4}} du So I get...
14. ### Changing Values & Variables

keeping in mid the variables, the values are changed accordingly to match the combinations & permutations. Manchester City vs Leicester City Newcastle United vs Manchester United QPR vs Arsenal Stoke City vs Everton Tottenham vs Swansea City West Ham United vs Chelsea Liverpool vs Burnley...
15. ### Two-way MANOVA - Total Effect of Independent Variables on Response Variables Together

I have run a two-way MANOVA in SPSS. In the model, there are two fixed (independent) variables A and B, and two response (dependent) variables X and Y. I am trying to ascertain the total effect of A and B on X and Y, i.e. A's effect on X and Y, plus B's effect on X and Y, plus A*B's interaction...
16. ### how to interpret coefficients in Mediation Analysis with logged variables

Hello there! I really hope u can help me because i've tried to find a solution to my problem for ages now.. i'm performing a mediation analysis with two regressions to get the coefficients a b and c. i know the interpretation of indirect effect (a*b) in mediation analysis when there is no...
17. ### difference of two independent Poisson random variables

Why the difference of two independent Poisson random variables doesn't have Poisson distribution? Demonstrate it.
18. ### Plotting functions of three variables

When plotting functions of three variables, we use level surfaces, because we can't really plot our "speed" values anywhere in the 3D coordinate system? So, in a way, surface plots can be called projections onto a lower dimension (third in this case). This is just like level curves, which are...
19. ### solving a system of 5 linear equations in 3 variables

Hello, I'm currently having trouble solving what I think is a complex system of Linear equations. I know how to solve a system of equations for two variable 2 equations, three variable three equations etc, but I have no idea how to solve a system of 5 linear equations for three variables. I've...
20. ### Limit of a function with two variables #1

$\displaystyle\lim_{(x,y)\to(0,0)}{\sin(x^2+y^2) \over x^2+y^2}$ If we use polar coordinate substitution then we get the value of 1. How do I prove it though?