Useful tips for everyday
What is the F-test statistic to compare the two models? The F-test, when used for regression analysis, lets you compare two competing regression models in…
What is expectation of sum of independent random variables? The expected value of the sum of several random variables is equal to the sum of…
Which is an example of a repeated measures ANOVA? The simplest example of a repeated measures design is a paired samples t-test: Each subject is…
How is autocorrelation detected in a time series? This phenomenon is known as autocorrelation (or serial correlation) and can sometimes be detected by plotting the…
How do you find the difference between two proportions? The difference between these sample proportions (females – males) is 0.53 – 0.34 = 0.19. Take…
What is the assumption for Cox regression model? One of the key assumptions of the Cox model is the proportional hazards function assumption. Specifically, the…
What is the difference between lag and differencing? Seasonal differencing. A seasonal difference is the difference between an observation and the previous observation from the…
How do you find the probability of a geometric distribution? p+q=1 p + q = 1 and q=1−p q = 1 − p . For…
What is a mediator analysis? Mediation analysis is a statistical method used to quantify the causal sequence by which an antecedent variable causes a mediating…
What is the most common metric for forecast accuracy? Mean absolute percentage error (MAPE) is akin to the MAD metric, but expresses the forecast error…