t test

1. Which T-Test is appropriate

Hello, I am trying to determine the effectiveness of one method versus another on the same data set, but I am confused which of the types of t-test I can use. I have heard about two-sample dependent t-test and two-sample independent t-test, and others, but to be honest I am confused. So, to...
2. Paired or unpaired test?

Forum experts, I'm doing some environmental data anlalysis and I'm struggling with the correct statistics approach. I have data from 4 3-week studies where a number of parameters were collection both upwind and downwind of an emissions site. I have 1-min data that I have also averaged into...
3. Combined t test for intercept and gradient - Unequal sample sizes, equal variance

I work in an industry where sales are related to temperature. My colleague has performed two regressions for sales: Monday to Thursday sales= a1 + b1*Temp Friday sales = a2 + b2*Temp I'm trying to determine whether Friday Sales are the same as Monday to Thursday sales. By 'the same' I...