# Search results

1. ### Lognormal distribution area within 1 standard deviation

For a normal distribution I understand that area to left or right of mean within 1 standard deviation is same. What about log normal distribution, is the area to left of mean and to the right of mean within one standard deviation the same also? If not what is the intuition?
2. ### Baisc R question regarding ARMA

This should be an easy question for expert users here. I am using the function 'arma' in R which appears as following in the documentation: arma(x, order = c(1, 1), lag = NULL, coef = NULL, include.intercept = TRUE, series = NULL, qr.tol = 1e-07, ...) For input 'x' do we...
3. ### Using ttest instead of R-Squared for acceptance

I have independent variable X and dependent variable Y. I am trying to compare the predictive power of a number of regression based models. For each model I obtain a R-Squared value. Also for each model I can obtain predicted Y (call it Y_new). What if I perform ttest on (Y_give - Y_new) to test...
4. ### Simple F test question

I have 3 data series A, B and C. How do I test whether the averages across A and B AND B and C etc. are jointly equal to one another using an F-test. I want to do this in R. Thanks
5. ### creating conditional probability distribution

I have a system which visits two locations and collects signals every 10 seconds. It is well known that A causes B to occur but not all the time. So, I am trying to find a conditional probability distribution of B given A. The data looks like following: A B ----------...
6. ### Correlation coeff vs. Logistic Regression Coeff.

From a bunch of data points which look like: 1 1 1 1 1 1 1 1 1 1 0 1 1 0 1 1 0 0 1 0 1 1 0 0 1 0 1 1 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 1 0 0 1 0 0 1 0 0 1 0 0 1 I get correlation coefficients as: 1 -0.301511345 0.204124145 -0.301511345 1 -0.287213479 0.204124145...
7. ### Correlation based on binary events

I have a system with 5 components. Every 10 seconds the signal travels to all of them and I know how many of them responded. I need to know there there is a correlation in response. So, my time series data looks something like: A B C D E ----------------------- 1 0 1...
8. ### Standard deviation of Sample vs. Standard deviation of mean

Hi, I have a very basic confusion. What exactly is the difference between them? Can you also give a simple example? Thanks guys