final exam Flashcards
what is a determinate error
it is a systematic error that is constantly off in one direction
what is an indeterminate error
it is an error that is always present but is random and not constantly off in one direction
what is uncertainty
it is a range of values of what it could be
what is explicit uncertainty
it is explicitly stated (+/- 0.003)
what is implicit uncertainty
it is implied by significant figures (531.025)
what is accuracy
how close we are to actual value
what is precision
how close our measurements are to eachother
what is a false positive error
when we say that the null hypothesis is false but its true
what is a false negative
when we say the null hypothesis is true but it is actually false
when do we use comparing x to u
when we are analyzying the difference between our mean and the reference value
when do we use f test
when we are testing if the standard deviations/ variances are different between two things
when do we use a unpaired t test
when we are analyzing the means between two methods and assume the variance is equal (one is not better than the other) but we want to see if they provide the same mean values
when do we use a paired t test
when we assume the means are not comparable but we want to analyze the difference or variances in the two methods
may be helpful in determining if one method is better than other (has a stronger variance in one direction)
when can we assume that the activities are one?
when the ionic strength is really low. So if you have really low concentrations of something, you can probably assume that the activities are 1
