# t-test

1. ### Thesis Help Request - Hypothesis Testing

Hi I am doing an event study and my null hypothesis is CAAR=0 and alternative is CAAR does not equal 0 (2 tailed t-test). CAAR is cumulative average abnormal returns. Can a two tailed test be used to give directional conclusions, e.g. if the CAAR value is 1.5% and is statistically significant at...
2. ### Sample size when adding two means

I want to compare a theoretical mean to a measured mean. But I determine this theoretical mean from adding two measured means. For example, let's say I want to determine if mixing a shade of white paint with a shade of black paint yields a particular gray paint (let’s pretend I can quantify...
3. ### What is the best statistical test/approach for pre- and post-intervention analysis?

Dear colleagues, We assessed several psychological measures (e.g. self-compassion scale, five-facets mindfulness questionnaire, satisfaction with life scale) before and after a Mindfulness-Based Psychoeducational Program for groups of people with acquired brain injuries. We would like to...
4. ### Paired test?

Hi, I have the following problem. In my experimental setup I have four tissue samples from the same animal in each experiment, two from one side and two from the other. The original plan is to apply a substance alone on a sample from one side and the substance mixed with the inhibitor on...

18. ### comparing test results obtained on the basis of different sample sizes

I have variables a1 and a2 with 57 observations each, and variables b1 and b2 with 29 observations each. I compare a1 with a2 by means of a paired-samples t-test, this gives p<0.001. Next, I compare b1 with b2 by means of a paired-samples t-test, this gives p>0.05 (actually p>0.10). I compared...
19. ### I need some help for my thesis about t-testing different data sets

Hello everybody, I'm conducting research on price dispersion to show that offline price dispersion is significantly smaller than online price disperison. I have up until today, monitored and collected over 1500 prices in excel on several homogeneous products in...
20. ### Assumptions for comparing means and which test to use

I am attempting to compare the means of soil moisture measured from two adjacent soil profiles at both 10cm and 30cm. Soil measurements were measured discretely six times over the course of two months at the same date and time for each profile. However, when looking to perform tests to compare...