Do any of the re-takers know how critical t-values are found on the exam? Do I have to look @ a table, are they given, do we have to calc… Can you even do that with a BAII+? I can plug and chug, but I’d like to know how I’m getting the numbers.
there will be no table for you to look at.
So either they give you the value from the table OR they give you an extract from the actual table, and you would use that to do the lookup. but by forcing you to do the lookup yourself, it’s really only testing if you know the proper df to use.
Remeber that they’re “two-ish”.
Isn’t the series 90%-95%-99%-99.7% = 1.65 - 1.96 - 2.58 - 3.00 ?
What is worse is remembering the formula
r * sqrt( n - 1 ) / sqrt ( 1 - r^2 )
But I try to remember it this way. I’m looking for how reliable the t-stat is, that is to say r^2. I’m looking for a large number, so I can reject the null hypothesis (which is rho = 0). If r^2 is as big as it gets, that is to say one, then I want an infinitely big number so the numerator must be (1 - r^2).
We now have r^2 / (1 - r^2). It’s a two-tailed test, so degrees of freedom is n - 2, I multiply the value with that number. Then I take the square root of it all:
sqrt ( (n-1) * r^2 / (1 - r^2) ) which is the same thing as the aforementioned formula.
It’s just a way to remember the formula…
is it n-1 or n-k-1…?
wawa it is sqrt(n-2) not sqrt(n-1)
Thanks… I’ve been doing the quick and dirty math, but I’ve seen a few examples where the formula is needed. I’m pretty concerned about now… 