## Solved – Statistical test for normalised data

I am working with culture cells where one dish has been transfected with a scrambled knockdown clone and two dishes which have been transfected with two knockdown clones each knocking down the expression of a single gene. An example of an experiment I have performed is to measure the mitochondrial membrane potential (using a fluorescent … Read more

## Solved – Why is the dickey fuller test different from a simple t-test

I am trying to understand why should there be different distribution for t-statistic, in case of AR model, Dickey-Fuller test For e.g. Say, the model is \$Y_t = beta_lY_{t-1} + varepsilon_{t}\$. Why should I not use Simple linear regression model like \$y_i = beta_0 + beta_1x_i+epsilon_i\$, where \$x_i = Y_{t-1} \$ and \$y_i = Y_t\$, … Read more

## Solved – How does the power of a logistic regression and a t-test compare

Is the power of a logistic regression and a t-test equivalent? If so, they should be "data density equivalent" by which I mean that the same number of underlying observations yields the same power given a fixed alpha of .05. Consider two cases: [The parametric t-test]: 30 draws from a binomial observation are made and … Read more

## Solved – the p-value for paired t-test if the two set of data are identical

As in the title, I have two sets of data that are identical. I performed a paired t-test using R. The p-value for the difference estimated (which is essentially 0) is NaN. I wonder if there can be a theoretical p-value for this case. Best Answer If the two sets of data are identical because … Read more

## Solved – the p-value for paired t-test if the two set of data are identical

As in the title, I have two sets of data that are identical. I performed a paired t-test using R. The p-value for the difference estimated (which is essentially 0) is NaN. I wonder if there can be a theoretical p-value for this case. Best Answer If the two sets of data are identical because … Read more

## Solved – Why is the Tukey confidence interval wider than the T-test confidence interval

I have two confidence intervals for a comparison of two means. The first is a t-test CI and the other is a Tukey CI. The Tukey CI \$(2.36, 26.5)\$ is wider than the t-test CI \$(6.46, 21.33)\$. What is the reason for this? Best Answer In the context of testing differences in group means on … Read more

## Solved – What distributions are for the slope and for the intercept in linear regression

In linear regression from a dataset \${ (x_i, y_i), i=1,cdots,N }\$, I wonder what distributions are for the slope and for the intercept? In Excel output, t-tests are used to tell whether the slope mean is zero and the intercept mean is zero. But t-test assumes the distributions of slope and of intercept are normal … Read more

## Solved – Some questions about two-sample comparisons

I am applying some statistical tests using python's scipy.stats library to some datasets that I have (taken in pairs), testing whether they both come from the same unknown distribution. I don't have much background in statistics, so forgive me for the following questions. I was looking at the documentation and I have some doubts. scipy.stats.mannwhitneyu: … Read more

## Solved – Some questions about two-sample comparisons

I am applying some statistical tests using python's scipy.stats library to some datasets that I have (taken in pairs), testing whether they both come from the same unknown distribution. I don't have much background in statistics, so forgive me for the following questions. I was looking at the documentation and I have some doubts. scipy.stats.mannwhitneyu: … Read more

## Solved – Clarification on t-test assumptions

I don't quite understand the assumptions of the t-test Wikipedia gives. I'm currently taking an intro statistics course, and when we covered t-tests, we learned the assumptions for a t-test are that: The population is assumed to be normally distributed Samples are random If there is deviation from either of the above, sample size must … Read more